Merge branch 'serial-from-alan'

* serial-from-alan: (79 commits) moxa: prevent opening unavailable ports imx: serial: use tty_encode_baud_rate to set true rate imx: serial: add IrDA support to serial driver imx: serial: use rational library function lib: isolate rational fractions helper function imx: serial: handle initialisation failure correctly imx: serial: be sure to stop xmit upon shutdown imx: serial: notify higher layers in case xmit IRQ was not called imx: serial: fix one bit field type imx: serial: fix whitespaces (no changes in functionality) tty: use prepare/finish_wait tty: remove sleep_on sierra: driver interface blacklisting sierra: driver urb handling improvements tty: resolve some sierra breakage timbuart: Fix the termios logic serial: Added Timberdale UART driver tty: Add URL for ttydev queue devpts: unregister the file system on error tty: Untangle termios and mm mutex dependencies ...
author: Linus Torvalds <torvalds@linux-foundation.org> 2009-06-11 08:57:47 -0700
committer: Linus Torvalds <torvalds@linux-foundation.org> 2009-06-11 08:57:47 -0700
commit: 49c355617f603b8e71ec117c1f940152a998528a (patch)
tree: 6b5e373003371bbe8c587a9fdda7bc4f0e791b03 /drivers/char
parent: 991ec02cdca33b03a132a0cacfe6f0aa0be9aa8d (diff)
parent: f0e8527726b9e56649b9eafde3bc0fbc4dd2dd47 (diff)
26 files changed, 1161 insertions, 579 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 735bbe2be51a..02ecfd5fa61c 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -97,6 +97,19 @@ config DEVKMEM
 	  kind of kernel debugging operations.
 	  When in doubt, say "N".
 
+config BFIN_JTAG_COMM
+	tristate "Blackfin JTAG Communication"
+	depends on BLACKFIN
+	help
+	  Add support for emulating a TTY device over the Blackfin JTAG.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called bfin_jtag_comm.
+
+config BFIN_JTAG_COMM_CONSOLE
+	bool "Console on Blackfin JTAG"
+	depends on BFIN_JTAG_COMM=y
+
 config SERIAL_NONSTANDARD
 	bool "Non-standard serial port support"
 	depends on HAS_IOMEM
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 9caf5b5ad1c0..189efcff08ce 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_LEGACY_PTYS)	+= pty.o
 obj-$(CONFIG_UNIX98_PTYS)	+= pty.o
 obj-y				+= misc.o
 obj-$(CONFIG_VT)		+= vt_ioctl.o vc_screen.o selection.o keyboard.o
+obj-$(CONFIG_BFIN_JTAG_COMM)	+= bfin_jtag_comm.o
 obj-$(CONFIG_CONSOLE_TRANSLATIONS) += consolemap.o consolemap_deftbl.o
 obj-$(CONFIG_HW_CONSOLE)	+= vt.o defkeymap.o
 obj-$(CONFIG_AUDIT)		+= tty_audit.o
diff --git a/drivers/char/bfin_jtag_comm.c b/drivers/char/bfin_jtag_comm.c
new file mode 100644
index 000000000000..44c113d56045
--- /dev/null
+++ b/drivers/char/bfin_jtag_comm.c
@@ -0,0 +1,365 @@
+/*
+ * TTY over Blackfin JTAG Communication
+ *
+ * Copyright 2008-2009 Analog Devices Inc.
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/circ_buf.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <asm/atomic.h>
+
+/* See the Debug/Emulation chapter in the HRM */
+#define EMUDOF   0x00000001	/* EMUDAT_OUT full & valid */
+#define EMUDIF   0x00000002	/* EMUDAT_IN full & valid */
+#define EMUDOOVF 0x00000004	/* EMUDAT_OUT overflow */
+#define EMUDIOVF 0x00000008	/* EMUDAT_IN overflow */
+
+#define DRV_NAME "bfin-jtag-comm"
+#define DEV_NAME "ttyBFJC"
+
+#define pr_init(fmt, args...) ({ static const __initdata char __fmt[] = fmt; printk(__fmt, ## args); })
+#define debug(fmt, args...) pr_debug(DRV_NAME ": " fmt, ## args)
+
+static inline uint32_t bfin_write_emudat(uint32_t emudat)
+{
+	__asm__ __volatile__("emudat = %0;" : : "d"(emudat));
+	return emudat;
+}
+
+static inline uint32_t bfin_read_emudat(void)
+{
+	uint32_t emudat;
+	__asm__ __volatile__("%0 = emudat;" : "=d"(emudat));
+	return emudat;
+}
+
+static inline uint32_t bfin_write_emudat_chars(char a, char b, char c, char d)
+{
+	return bfin_write_emudat((a << 0) | (b << 8) | (c << 16) | (d << 24));
+}
+
+#define CIRC_SIZE 2048	/* see comment in tty_io.c:do_tty_write() */
+#define CIRC_MASK (CIRC_SIZE - 1)
+#define circ_empty(circ)     ((circ)->head == (circ)->tail)
+#define circ_free(circ)      CIRC_SPACE((circ)->head, (circ)->tail, CIRC_SIZE)
+#define circ_cnt(circ)       CIRC_CNT((circ)->head, (circ)->tail, CIRC_SIZE)
+#define circ_byte(circ, idx) ((circ)->buf[(idx) & CIRC_MASK])
+
+static struct tty_driver *bfin_jc_driver;
+static struct task_struct *bfin_jc_kthread;
+static struct tty_struct * volatile bfin_jc_tty;
+static unsigned long bfin_jc_count;
+static DEFINE_MUTEX(bfin_jc_tty_mutex);
+static volatile struct circ_buf bfin_jc_write_buf;
+
+static int
+bfin_jc_emudat_manager(void *arg)
+{
+	uint32_t inbound_len = 0, outbound_len = 0;
+
+	while (!kthread_should_stop()) {
+		/* no one left to give data to, so sleep */
+		if (bfin_jc_tty == NULL && circ_empty(&bfin_jc_write_buf)) {
+			debug("waiting for readers\n");
+			__set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule();
+			__set_current_state(TASK_RUNNING);
+		}
+
+		/* no data available, so just chill */
+		if (!(bfin_read_DBGSTAT() & EMUDIF) && circ_empty(&bfin_jc_write_buf)) {
+			debug("waiting for data (in_len = %i) (circ: %i %i)\n",
+				inbound_len, bfin_jc_write_buf.tail, bfin_jc_write_buf.head);
+			if (inbound_len)
+				schedule();
+			else
+				schedule_timeout_interruptible(HZ);
+			continue;
+		}
+
+		/* if incoming data is ready, eat it */
+		if (bfin_read_DBGSTAT() & EMUDIF) {
+			struct tty_struct *tty;
+			mutex_lock(&bfin_jc_tty_mutex);
+			tty = (struct tty_struct *)bfin_jc_tty;
+			if (tty != NULL) {
+				uint32_t emudat = bfin_read_emudat();
+				if (inbound_len == 0) {
+					debug("incoming length: 0x%08x\n", emudat);
+					inbound_len = emudat;
+				} else {
+					size_t num_chars = (4 <= inbound_len ? 4 : inbound_len);
+					debug("  incoming data: 0x%08x (pushing %zu)\n", emudat, num_chars);
+					inbound_len -= num_chars;
+					tty_insert_flip_string(tty, (unsigned char *)&emudat, num_chars);
+					tty_flip_buffer_push(tty);
+				}
+			}
+			mutex_unlock(&bfin_jc_tty_mutex);
+		}
+
+		/* if outgoing data is ready, post it */
+		if (!(bfin_read_DBGSTAT() & EMUDOF) && !circ_empty(&bfin_jc_write_buf)) {
+			if (outbound_len == 0) {
+				outbound_len = circ_cnt(&bfin_jc_write_buf);
+				bfin_write_emudat(outbound_len);
+				debug("outgoing length: 0x%08x\n", outbound_len);
+			} else {
+				struct tty_struct *tty;
+				int tail = bfin_jc_write_buf.tail;
+				size_t ate = (4 <= outbound_len ? 4 : outbound_len);
+				uint32_t emudat =
+				bfin_write_emudat_chars(
+					circ_byte(&bfin_jc_write_buf, tail + 0),
+					circ_byte(&bfin_jc_write_buf, tail + 1),
+					circ_byte(&bfin_jc_write_buf, tail + 2),
+					circ_byte(&bfin_jc_write_buf, tail + 3)
+				);
+				bfin_jc_write_buf.tail += ate;
+				outbound_len -= ate;
+				mutex_lock(&bfin_jc_tty_mutex);
+				tty = (struct tty_struct *)bfin_jc_tty;
+				if (tty)
+					tty_wakeup(tty);
+				mutex_unlock(&bfin_jc_tty_mutex);
+				debug("  outgoing data: 0x%08x (pushing %zu)\n", emudat, ate);
+			}
+		}
+	}
+
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
+static int
+bfin_jc_open(struct tty_struct *tty, struct file *filp)
+{
+	mutex_lock(&bfin_jc_tty_mutex);
+	debug("open %lu\n", bfin_jc_count);
+	++bfin_jc_count;
+	bfin_jc_tty = tty;
+	wake_up_process(bfin_jc_kthread);
+	mutex_unlock(&bfin_jc_tty_mutex);
+	return 0;
+}
+
+static void
+bfin_jc_close(struct tty_struct *tty, struct file *filp)
+{
+	mutex_lock(&bfin_jc_tty_mutex);
+	debug("close %lu\n", bfin_jc_count);
+	if (--bfin_jc_count == 0)
+		bfin_jc_tty = NULL;
+	wake_up_process(bfin_jc_kthread);
+	mutex_unlock(&bfin_jc_tty_mutex);
+}
+
+/* XXX: we dont handle the put_char() case where we must handle count = 1 */
+static int
+bfin_jc_circ_write(const unsigned char *buf, int count)
+{
+	int i;
+	count = min(count, circ_free(&bfin_jc_write_buf));
+	debug("going to write chunk of %i bytes\n", count);
+	for (i = 0; i < count; ++i)
+		circ_byte(&bfin_jc_write_buf, bfin_jc_write_buf.head + i) = buf[i];
+	bfin_jc_write_buf.head += i;
+	return i;
+}
+
+#ifndef CONFIG_BFIN_JTAG_COMM_CONSOLE
+# define acquire_console_sem()
+# define release_console_sem()
+#endif
+static int
+bfin_jc_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+	int i;
+	acquire_console_sem();
+	i = bfin_jc_circ_write(buf, count);
+	release_console_sem();
+	wake_up_process(bfin_jc_kthread);
+	return i;
+}
+
+static void
+bfin_jc_flush_chars(struct tty_struct *tty)
+{
+	wake_up_process(bfin_jc_kthread);
+}
+
+static int
+bfin_jc_write_room(struct tty_struct *tty)
+{
+	return circ_free(&bfin_jc_write_buf);
+}
+
+static int
+bfin_jc_chars_in_buffer(struct tty_struct *tty)
+{
+	return circ_cnt(&bfin_jc_write_buf);
+}
+
+static void
+bfin_jc_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	unsigned long expire = jiffies + timeout;
+	while (!circ_empty(&bfin_jc_write_buf)) {
+		if (signal_pending(current))
+			break;
+		if (time_after(jiffies, expire))
+			break;
+	}
+}
+
+static struct tty_operations bfin_jc_ops = {
+	.open            = bfin_jc_open,
+	.close           = bfin_jc_close,
+	.write           = bfin_jc_write,
+	/*.put_char        = bfin_jc_put_char,*/
+	.flush_chars     = bfin_jc_flush_chars,
+	.write_room      = bfin_jc_write_room,
+	.chars_in_buffer = bfin_jc_chars_in_buffer,
+	.wait_until_sent = bfin_jc_wait_until_sent,
+};
+
+static int __init bfin_jc_init(void)
+{
+	int ret;
+
+	bfin_jc_kthread = kthread_create(bfin_jc_emudat_manager, NULL, DRV_NAME);
+	if (IS_ERR(bfin_jc_kthread))
+		return PTR_ERR(bfin_jc_kthread);
+
+	ret = -ENOMEM;
+
+	bfin_jc_write_buf.head = bfin_jc_write_buf.tail = 0;
+	bfin_jc_write_buf.buf = kmalloc(CIRC_SIZE, GFP_KERNEL);
+	if (!bfin_jc_write_buf.buf)
+		goto err;
+
+	bfin_jc_driver = alloc_tty_driver(1);
+	if (!bfin_jc_driver)
+		goto err;
+
+	bfin_jc_driver->owner        = THIS_MODULE;
+	bfin_jc_driver->driver_name  = DRV_NAME;
+	bfin_jc_driver->name         = DEV_NAME;
+	bfin_jc_driver->type         = TTY_DRIVER_TYPE_SERIAL;
+	bfin_jc_driver->subtype      = SERIAL_TYPE_NORMAL;
+	bfin_jc_driver->init_termios = tty_std_termios;
+	tty_set_operations(bfin_jc_driver, &bfin_jc_ops);
+
+	ret = tty_register_driver(bfin_jc_driver);
+	if (ret)
+		goto err;
+
+	pr_init(KERN_INFO DRV_NAME ": initialized\n");
+
+	return 0;
+
+ err:
+	put_tty_driver(bfin_jc_driver);
+	kfree(bfin_jc_write_buf.buf);
+	kthread_stop(bfin_jc_kthread);
+	return ret;
+}
+module_init(bfin_jc_init);
+
+static void __exit bfin_jc_exit(void)
+{
+	kthread_stop(bfin_jc_kthread);
+	kfree(bfin_jc_write_buf.buf);
+	tty_unregister_driver(bfin_jc_driver);
+	put_tty_driver(bfin_jc_driver);
+}
+module_exit(bfin_jc_exit);
+
+#if defined(CONFIG_BFIN_JTAG_COMM_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
+static void
+bfin_jc_straight_buffer_write(const char *buf, unsigned count)
+{
+	unsigned ate = 0;
+	while (bfin_read_DBGSTAT() & EMUDOF)
+		continue;
+	bfin_write_emudat(count);
+	while (ate < count) {
+		while (bfin_read_DBGSTAT() & EMUDOF)
+			continue;
+		bfin_write_emudat_chars(buf[ate], buf[ate+1], buf[ate+2], buf[ate+3]);
+		ate += 4;
+	}
+}
+#endif
+
+#ifdef CONFIG_BFIN_JTAG_COMM_CONSOLE
+static void
+bfin_jc_console_write(struct console *co, const char *buf, unsigned count)
+{
+	if (bfin_jc_kthread == NULL)
+		bfin_jc_straight_buffer_write(buf, count);
+	else
+		bfin_jc_circ_write(buf, count);
+}
+
+static struct tty_driver *
+bfin_jc_console_device(struct console *co, int *index)
+{
+	*index = co->index;
+	return bfin_jc_driver;
+}
+
+static struct console bfin_jc_console = {
+	.name    = DEV_NAME,
+	.write   = bfin_jc_console_write,
+	.device  = bfin_jc_console_device,
+	.flags   = CON_ANYTIME | CON_PRINTBUFFER,
+	.index   = -1,
+};
+
+static int __init bfin_jc_console_init(void)
+{
+	register_console(&bfin_jc_console);
+	return 0;
+}
+console_initcall(bfin_jc_console_init);
+#endif
+
+#ifdef CONFIG_EARLY_PRINTK
+static void __init
+bfin_jc_early_write(struct console *co, const char *buf, unsigned int count)
+{
+	bfin_jc_straight_buffer_write(buf, count);
+}
+
+static struct __initdata console bfin_jc_early_console = {
+	.name   = "early_BFJC",
+	.write   = bfin_jc_early_write,
+	.flags   = CON_ANYTIME | CON_PRINTBUFFER,
+	.index   = -1,
+};
+
+struct console * __init
+bfin_jc_early_init(unsigned int port, unsigned int cflag)
+{
+	return &bfin_jc_early_console;
+}
+#endif
+
+MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
+MODULE_DESCRIPTION("TTY over Blackfin JTAG Communication");
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index 1fdb9f657d8f..f3366d3f06cf 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -604,7 +604,6 @@
 
 #define NR_PORTS	256
 
-#define ZE_V1_NPORTS	64
 #define ZO_V1	0
 #define ZO_V2	1
 #define ZE_V1	2
@@ -663,18 +662,6 @@
 static void cy_throttle(struct tty_struct *tty);
 static void cy_send_xchar(struct tty_struct *tty, char ch);
 
-#define IS_CYC_Z(card) ((card).num_chips == (unsigned int)-1)
-
-#define Z_FPGA_CHECK(card) \
-	((readl(&((struct RUNTIME_9060 __iomem *) \
-		((card).ctl_addr))->init_ctrl) & (1<<17)) != 0)
-
-#define ISZLOADED(card)	(((ZO_V1 == readl(&((struct RUNTIME_9060 __iomem *) \
-			((card).ctl_addr))->mail_box_0)) || \
-			Z_FPGA_CHECK(card)) && \
-			(ZFIRM_ID == readl(&((struct FIRM_ID __iomem *) \
-			((card).base_addr+ID_ADDRESS))->signature)))
-
 #ifndef SERIAL_XMIT_SIZE
 #define	SERIAL_XMIT_SIZE	(min(PAGE_SIZE, 4096))
 #endif
@@ -687,8 +674,6 @@ static void cy_send_xchar(struct tty_struct *tty, char ch);
 #define DRIVER_VERSION	0x02010203
 #define RAM_SIZE 0x80000
 
-#define Z_FPGA_LOADED(X)	((readl(&(X)->init_ctrl) & (1<<17)) != 0)
-
 enum zblock_type {
 	ZBLOCK_PRG = 0,
 	ZBLOCK_FPGA = 1
@@ -883,6 +868,29 @@ static void cyz_rx_restart(unsigned long);
 static struct timer_list cyz_rx_full_timer[NR_PORTS];
 #endif				/* CONFIG_CYZ_INTR */
 
+static inline bool cy_is_Z(struct cyclades_card *card)
+{
+	return card->num_chips == (unsigned int)-1;
+}
+
+static inline bool __cyz_fpga_loaded(struct RUNTIME_9060 __iomem *ctl_addr)
+{
+	return readl(&ctl_addr->init_ctrl) & (1 << 17);
+}
+
+static inline bool cyz_fpga_loaded(struct cyclades_card *card)
+{
+	return __cyz_fpga_loaded(card->ctl_addr.p9060);
+}
+
+static inline bool cyz_is_loaded(struct cyclades_card *card)
+{
+	struct FIRM_ID __iomem *fw_id = card->base_addr + ID_ADDRESS;
+
+	return (card->hw_ver == ZO_V1 || cyz_fpga_loaded(card)) &&
+			readl(&fw_id->signature) == ZFIRM_ID;
+}
+
 static inline int serial_paranoia_check(struct cyclades_port *info,
 		char *name, const char *routine)
 {
@@ -1395,19 +1403,15 @@ cyz_fetch_msg(struct cyclades_card *cinfo,
 	unsigned long loc_doorbell;
 
 	firm_id = cinfo->base_addr + ID_ADDRESS;
-	if (!ISZLOADED(*cinfo))
-		return -1;
 	zfw_ctrl = cinfo->base_addr + (readl(&firm_id->zfwctrl_addr) & 0xfffff);
 	board_ctrl = &zfw_ctrl->board_ctrl;
 
-	loc_doorbell = readl(&((struct RUNTIME_9060 __iomem *)
-				  (cinfo->ctl_addr))->loc_doorbell);
+	loc_doorbell = readl(&cinfo->ctl_addr.p9060->loc_doorbell);
 	if (loc_doorbell) {
 		*cmd = (char)(0xff & loc_doorbell);
 		*channel = readl(&board_ctrl->fwcmd_channel);
 		*param = (__u32) readl(&board_ctrl->fwcmd_param);
-		cy_writel(&((struct RUNTIME_9060 __iomem *)(cinfo->ctl_addr))->
-			  loc_doorbell, 0xffffffff);
+		cy_writel(&cinfo->ctl_addr.p9060->loc_doorbell, 0xffffffff);
 		return 1;
 	}
 	return 0;
@@ -1424,15 +1428,14 @@ cyz_issue_cmd(struct cyclades_card *cinfo,
 	unsigned int index;
 
 	firm_id = cinfo->base_addr + ID_ADDRESS;
-	if (!ISZLOADED(*cinfo))
+	if (!cyz_is_loaded(cinfo))
 		return -1;
 
 	zfw_ctrl = cinfo->base_addr + (readl(&firm_id->zfwctrl_addr) & 0xfffff);
 	board_ctrl = &zfw_ctrl->board_ctrl;
 
 	index = 0;
-	pci_doorbell =
-	    &((struct RUNTIME_9060 __iomem *)(cinfo->ctl_addr))->pci_doorbell;
+	pci_doorbell = &cinfo->ctl_addr.p9060->pci_doorbell;
 	while ((readl(pci_doorbell) & 0xff) != 0) {
 		if (index++ == 1000)
 			return (int)(readl(pci_doorbell) & 0xff);
@@ -1624,10 +1627,8 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
 	static struct BOARD_CTRL __iomem *board_ctrl;
 	static struct CH_CTRL __iomem *ch_ctrl;
 	static struct BUF_CTRL __iomem *buf_ctrl;
-	__u32 channel;
+	__u32 channel, param, fw_ver;
 	__u8 cmd;
-	__u32 param;
-	__u32 hw_ver, fw_ver;
 	int special_count;
 	int delta_count;
 
@@ -1635,8 +1636,6 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
 	zfw_ctrl = cinfo->base_addr + (readl(&firm_id->zfwctrl_addr) & 0xfffff);
 	board_ctrl = &zfw_ctrl->board_ctrl;
 	fw_ver = readl(&board_ctrl->fw_version);
-	hw_ver = readl(&((struct RUNTIME_9060 __iomem *)(cinfo->ctl_addr))->
-			mail_box_0);
 
 	while (cyz_fetch_msg(cinfo, &channel, &cmd, &param) == 1) {
 		special_count = 0;
@@ -1737,15 +1736,7 @@ static irqreturn_t cyz_interrupt(int irq, void *dev_id)
 {
 	struct cyclades_card *cinfo = dev_id;
 
-	if (unlikely(cinfo == NULL)) {
-#ifdef CY_DEBUG_INTERRUPTS
-		printk(KERN_DEBUG "cyz_interrupt: spurious interrupt %d\n",
-									irq);
-#endif
-		return IRQ_NONE;	/* spurious interrupt */
-	}
-
-	if (unlikely(!ISZLOADED(*cinfo))) {
+	if (unlikely(!cyz_is_loaded(cinfo))) {
 #ifdef CY_DEBUG_INTERRUPTS
 		printk(KERN_DEBUG "cyz_interrupt: board not yet loaded "
 				"(IRQ%d).\n", irq);
@@ -1785,7 +1776,6 @@ static void cyz_poll(unsigned long arg)
 	struct tty_struct *tty;
 	struct FIRM_ID __iomem *firm_id;
 	struct ZFW_CTRL __iomem *zfw_ctrl;
-	struct BOARD_CTRL __iomem *board_ctrl;
 	struct BUF_CTRL __iomem *buf_ctrl;
 	unsigned long expires = jiffies + HZ;
 	unsigned int port, card;
@@ -1793,19 +1783,17 @@ static void cyz_poll(unsigned long arg)
 	for (card = 0; card < NR_CARDS; card++) {
 		cinfo = &cy_card[card];
 
-		if (!IS_CYC_Z(*cinfo))
+		if (!cy_is_Z(cinfo))
 			continue;
-		if (!ISZLOADED(*cinfo))
+		if (!cyz_is_loaded(cinfo))
 			continue;
 
 		firm_id = cinfo->base_addr + ID_ADDRESS;
 		zfw_ctrl = cinfo->base_addr +
 				(readl(&firm_id->zfwctrl_addr) & 0xfffff);
-		board_ctrl = &(zfw_ctrl->board_ctrl);
 
 	/* Skip first polling cycle to avoid racing conditions with the FW */
 		if (!cinfo->intr_enabled) {
-			cinfo->nports = (int)readl(&board_ctrl->n_channel);
 			cinfo->intr_enabled = 1;
 			continue;
 		}
@@ -1874,7 +1862,7 @@ static int startup(struct cyclades_port *info)
 
 	set_line_char(info);
 
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -1931,7 +1919,7 @@ static int startup(struct cyclades_port *info)
 		base_addr = card->base_addr;
 
 		firm_id = base_addr + ID_ADDRESS;
-		if (!ISZLOADED(*card))
+		if (!cyz_is_loaded(card))
 			return -ENODEV;
 
 		zfw_ctrl = card->base_addr +
@@ -2026,7 +2014,7 @@ static void start_xmit(struct cyclades_port *info)
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -2070,7 +2058,7 @@ static void shutdown(struct cyclades_port *info)
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -2126,7 +2114,7 @@ static void shutdown(struct cyclades_port *info)
 #endif
 
 		firm_id = base_addr + ID_ADDRESS;
-		if (!ISZLOADED(*card))
+		if (!cyz_is_loaded(card))
 			return;
 
 		zfw_ctrl = card->base_addr +
@@ -2233,7 +2221,7 @@ block_til_ready(struct tty_struct *tty, struct file *filp,
 #endif
 	info->port.blocked_open++;
 
-	if (!IS_CYC_Z(*cinfo)) {
+	if (!cy_is_Z(cinfo)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = cinfo->bus_index;
@@ -2296,7 +2284,7 @@ block_til_ready(struct tty_struct *tty, struct file *filp,
 
 		base_addr = cinfo->base_addr;
 		firm_id = base_addr + ID_ADDRESS;
-		if (!ISZLOADED(*cinfo)) {
+		if (!cyz_is_loaded(cinfo)) {
 			__set_current_state(TASK_RUNNING);
 			remove_wait_queue(&info->port.open_wait, &wait);
 			return -EINVAL;
@@ -2397,16 +2385,14 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
 	   treat it as absent from the system.  This
 	   will make the user pay attention.
 	 */
-	if (IS_CYC_Z(*info->card)) {
+	if (cy_is_Z(info->card)) {
 		struct cyclades_card *cinfo = info->card;
 		struct FIRM_ID __iomem *firm_id = cinfo->base_addr + ID_ADDRESS;
 
-		if (!ISZLOADED(*cinfo)) {
-			if (((ZE_V1 == readl(&((struct RUNTIME_9060 __iomem *)
-					 (cinfo->ctl_addr))->mail_box_0)) &&
-					Z_FPGA_CHECK(*cinfo)) &&
-					(ZFIRM_HLT == readl(
-						&firm_id->signature))) {
+		if (!cyz_is_loaded(cinfo)) {
+			if (cinfo->hw_ver == ZE_V1 && cyz_fpga_loaded(cinfo) &&
+					readl(&firm_id->signature) ==
+					ZFIRM_HLT) {
 				printk(KERN_ERR "cyc:Cyclades-Z Error: you "
 					"need an external power supply for "
 					"this number of ports.\nFirmware "
@@ -2423,18 +2409,13 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
 		   interrupts should be enabled as soon as the first open
 		   happens to one of its ports. */
 			if (!cinfo->intr_enabled) {
-				struct ZFW_CTRL __iomem *zfw_ctrl;
-				struct BOARD_CTRL __iomem *board_ctrl;
-
-				zfw_ctrl = cinfo->base_addr +
-					(readl(&firm_id->zfwctrl_addr) &
-					 0xfffff);
-
-				board_ctrl = &zfw_ctrl->board_ctrl;
+				u16 intr;
 
 				/* Enable interrupts on the PLX chip */
-				cy_writew(cinfo->ctl_addr + 0x68,
-					readw(cinfo->ctl_addr + 0x68) | 0x0900);
+				intr = readw(&cinfo->ctl_addr.p9060->
+						intr_ctrl_stat) | 0x0900;
+				cy_writew(&cinfo->ctl_addr.p9060->
+						intr_ctrl_stat, intr);
 				/* Enable interrupts on the FW */
 				retval = cyz_issue_cmd(cinfo, 0,
 						C_CM_IRQ_ENBL, 0L);
@@ -2442,8 +2423,6 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
 					printk(KERN_ERR "cyc:IRQ enable retval "
 						"was %x\n", retval);
 				}
-				cinfo->nports =
-					(int)readl(&board_ctrl->n_channel);
 				cinfo->intr_enabled = 1;
 			}
 		}
@@ -2556,7 +2535,7 @@ static void cy_wait_until_sent(struct tty_struct *tty, int timeout)
 #endif
 	card = info->card;
 	channel = (info->line) - (card->first_line);
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -2601,7 +2580,7 @@ static void cy_flush_buffer(struct tty_struct *tty)
 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 	spin_unlock_irqrestore(&card->card_lock, flags);
 
-	if (IS_CYC_Z(*card)) {	/* If it is a Z card, flush the on-board
+	if (cy_is_Z(card)) {	/* If it is a Z card, flush the on-board
 					   buffers as well */
 		spin_lock_irqsave(&card->card_lock, flags);
 		retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);
@@ -2682,7 +2661,7 @@ static void cy_close(struct tty_struct *tty, struct file *filp)
 
 	spin_lock_irqsave(&card->card_lock, flags);
 
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		int channel = info->line - card->first_line;
 		int index = card->bus_index;
 		void __iomem *base_addr = card->base_addr +
@@ -2902,7 +2881,7 @@ static int cy_chars_in_buffer(struct tty_struct *tty)
 	channel = (info->line) - (card->first_line);
 
 #ifdef Z_EXT_CHARS_IN_BUFFER
-	if (!IS_CYC_Z(cy_card[card])) {
+	if (!cy_is_Z(card)) {
 #endif				/* Z_EXT_CHARS_IN_BUFFER */
 #ifdef CY_DEBUG_IO
 		printk(KERN_DEBUG "cyc:cy_chars_in_buffer ttyC%d %d\n",
@@ -2984,7 +2963,6 @@ static void set_line_char(struct cyclades_port *info)
 	void __iomem *base_addr;
 	int chip, channel, index;
 	unsigned cflag, iflag;
-	unsigned short chip_number;
 	int baud, baud_rate = 0;
 	int i;
 
@@ -3013,9 +2991,8 @@ static void set_line_char(struct cyclades_port *info)
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	chip_number = channel / 4;
 
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 
 		index = card->bus_index;
 
@@ -3233,21 +3210,17 @@ static void set_line_char(struct cyclades_port *info)
 	} else {
 		struct FIRM_ID __iomem *firm_id;
 		struct ZFW_CTRL __iomem *zfw_ctrl;
-		struct BOARD_CTRL __iomem *board_ctrl;
 		struct CH_CTRL __iomem *ch_ctrl;
-		struct BUF_CTRL __iomem *buf_ctrl;
 		__u32 sw_flow;
 		int retval;
 
 		firm_id = card->base_addr + ID_ADDRESS;
-		if (!ISZLOADED(*card))
+		if (!cyz_is_loaded(card))
 			return;
 
 		zfw_ctrl = card->base_addr +
 			(readl(&firm_id->zfwctrl_addr) & 0xfffff);
-		board_ctrl = &zfw_ctrl->board_ctrl;
 		ch_ctrl = &(zfw_ctrl->ch_ctrl[channel]);
-		buf_ctrl = &zfw_ctrl->buf_ctrl[channel];
 
 		/* baud rate */
 		baud = tty_get_baud_rate(info->port.tty);
@@ -3457,7 +3430,7 @@ static int get_lsr_info(struct cyclades_port *info, unsigned int __user *value)
 
 	card = info->card;
 	channel = (info->line) - (card->first_line);
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -3497,7 +3470,7 @@ static int cy_tiocmget(struct tty_struct *tty, struct file *file)
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -3523,7 +3496,7 @@ static int cy_tiocmget(struct tty_struct *tty, struct file *file)
 	} else {
 		base_addr = card->base_addr;
 		firm_id = card->base_addr + ID_ADDRESS;
-		if (ISZLOADED(*card)) {
+		if (cyz_is_loaded(card)) {
 			zfw_ctrl = card->base_addr +
 				(readl(&firm_id->zfwctrl_addr) & 0xfffff);
 			board_ctrl = &zfw_ctrl->board_ctrl;
@@ -3566,7 +3539,7 @@ cy_tiocmset(struct tty_struct *tty, struct file *file,
 
 	card = info->card;
 	channel = (info->line) - (card->first_line);
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -3641,7 +3614,7 @@ cy_tiocmset(struct tty_struct *tty, struct file *file,
 		base_addr = card->base_addr;
 
 		firm_id = card->base_addr + ID_ADDRESS;
-		if (ISZLOADED(*card)) {
+		if (cyz_is_loaded(card)) {
 			zfw_ctrl = card->base_addr +
 				(readl(&firm_id->zfwctrl_addr) & 0xfffff);
 			board_ctrl = &zfw_ctrl->board_ctrl;
@@ -3713,7 +3686,7 @@ static int cy_break(struct tty_struct *tty, int break_state)
 	card = info->card;
 
 	spin_lock_irqsave(&card->card_lock, flags);
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		/* Let the transmit ISR take care of this (since it
 		   requires stuffing characters into the output stream).
 		 */
@@ -3782,7 +3755,7 @@ static int set_threshold(struct cyclades_port *info, unsigned long value)
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -3810,7 +3783,7 @@ static int get_threshold(struct cyclades_port *info,
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -3844,7 +3817,7 @@ static int set_timeout(struct cyclades_port *info, unsigned long value)
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -3867,7 +3840,7 @@ static int get_timeout(struct cyclades_port *info,
 
 	card = info->card;
 	channel = info->line - card->first_line;
-	if (!IS_CYC_Z(*card)) {
+	if (!cy_is_Z(card)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		index = card->bus_index;
@@ -4121,7 +4094,7 @@ static void cy_send_xchar(struct tty_struct *tty, char ch)
 	card = info->card;
 	channel = info->line - card->first_line;
 
-	if (IS_CYC_Z(*card)) {
+	if (cy_is_Z(card)) {
 		if (ch == STOP_CHAR(tty))
 			cyz_issue_cmd(card, channel, C_CM_SENDXOFF, 0L);
 		else if (ch == START_CHAR(tty))
@@ -4154,7 +4127,7 @@ static void cy_throttle(struct tty_struct *tty)
 	card = info->card;
 
 	if (I_IXOFF(tty)) {
-		if (!IS_CYC_Z(*card))
+		if (!cy_is_Z(card))
 			cy_send_xchar(tty, STOP_CHAR(tty));
 		else
 			info->throttle = 1;
@@ -4162,7 +4135,7 @@ static void cy_throttle(struct tty_struct *tty)
 
 	if (tty->termios->c_cflag & CRTSCTS) {
 		channel = info->line - card->first_line;
-		if (!IS_CYC_Z(*card)) {
+		if (!cy_is_Z(card)) {
 			chip = channel >> 2;
 			channel &= 0x03;
 			index = card->bus_index;
@@ -4219,7 +4192,7 @@ static void cy_unthrottle(struct tty_struct *tty)
 	if (tty->termios->c_cflag & CRTSCTS) {
 		card = info->card;
 		channel = info->line - card->first_line;
-		if (!IS_CYC_Z(*card)) {
+		if (!cy_is_Z(card)) {
 			chip = channel >> 2;
 			channel &= 0x03;
 			index = card->bus_index;
@@ -4263,7 +4236,7 @@ static void cy_stop(struct tty_struct *tty)
 
 	cinfo = info->card;
 	channel = info->line - cinfo->first_line;
-	if (!IS_CYC_Z(*cinfo)) {
+	if (!cy_is_Z(cinfo)) {
 		index = cinfo->bus_index;
 		chip = channel >> 2;
 		channel &= 0x03;
@@ -4296,7 +4269,7 @@ static void cy_start(struct tty_struct *tty)
 	cinfo = info->card;
 	channel = info->line - cinfo->first_line;
 	index = cinfo->bus_index;
-	if (!IS_CYC_Z(*cinfo)) {
+	if (!cy_is_Z(cinfo)) {
 		chip = channel >> 2;
 		channel &= 0x03;
 		base_addr = cinfo->base_addr + (cy_chip_offset[chip] << index);
@@ -4347,33 +4320,20 @@ static void cy_hangup(struct tty_struct *tty)
 static int __devinit cy_init_card(struct cyclades_card *cinfo)
 {
 	struct cyclades_port *info;
-	u32 uninitialized_var(mailbox);
-	unsigned int nports, port;
+	unsigned int port;
 	unsigned short chip_number;
-	int uninitialized_var(index);
 
 	spin_lock_init(&cinfo->card_lock);
+	cinfo->intr_enabled = 0;
 
-	if (IS_CYC_Z(*cinfo)) {	/* Cyclades-Z */
-		mailbox = readl(&((struct RUNTIME_9060 __iomem *)
-				     cinfo->ctl_addr)->mail_box_0);
-		nports = (mailbox == ZE_V1) ? ZE_V1_NPORTS : 8;
-		cinfo->intr_enabled = 0;
-		cinfo->nports = 0;	/* Will be correctly set later, after
-					   Z FW is loaded */
-	} else {
-		index = cinfo->bus_index;
-		nports = cinfo->nports = CyPORTS_PER_CHIP * cinfo->num_chips;
-	}
-
-	cinfo->ports = kzalloc(sizeof(*cinfo->ports) * nports, GFP_KERNEL);
+	cinfo->ports = kcalloc(cinfo->nports, sizeof(*cinfo->ports),
+			GFP_KERNEL);
 	if (cinfo->ports == NULL) {
 		printk(KERN_ERR "Cyclades: cannot allocate ports\n");
-		cinfo->nports = 0;
 		return -ENOMEM;
 	}
 
-	for (port = cinfo->first_line; port < cinfo->first_line + nports;
+	for (port = cinfo->first_line; port < cinfo->first_line + cinfo->nports;
 			port++) {
 		info = &cinfo->ports[port - cinfo->first_line];
 		tty_port_init(&info->port);
@@ -4387,9 +4347,9 @@ static int __devinit cy_init_card(struct cyclades_card *cinfo)
 		init_completion(&info->shutdown_wait);
 		init_waitqueue_head(&info->delta_msr_wait);
 
-		if (IS_CYC_Z(*cinfo)) {
+		if (cy_is_Z(cinfo)) {
 			info->type = PORT_STARTECH;
-			if (mailbox == ZO_V1)
+			if (cinfo->hw_ver == ZO_V1)
 				info->xmit_fifo_size = CYZ_FIFO_SIZE;
 			else
 				info->xmit_fifo_size = 4 * CYZ_FIFO_SIZE;
@@ -4398,6 +4358,7 @@ static int __devinit cy_init_card(struct cyclades_card *cinfo)
 				cyz_rx_restart, (unsigned long)info);
 #endif
 		} else {
+			int index = cinfo->bus_index;
 			info->type = PORT_CIRRUS;
 			info->xmit_fifo_size = CyMAX_CHAR_FIFO;
 			info->cor1 = CyPARITY_NONE | Cy_1_STOP | Cy_8_BITS;
@@ -4430,7 +4391,7 @@ static int __devinit cy_init_card(struct cyclades_card *cinfo)
 	}
 
 #ifndef CONFIG_CYZ_INTR
-	if (IS_CYC_Z(*cinfo) && !timer_pending(&cyz_timerlist)) {
+	if (cy_is_Z(cinfo) && !timer_pending(&cyz_timerlist)) {
 		mod_timer(&cyz_timerlist, jiffies + 1);
 #ifdef CY_PCI_DEBUG
 		printk(KERN_DEBUG "Cyclades-Z polling initialized\n");
@@ -4621,11 +4582,12 @@ static int __init cy_detect_isa(void)
 
 		/* set cy_card */
 		cy_card[j].base_addr = cy_isa_address;
-		cy_card[j].ctl_addr = NULL;
+		cy_card[j].ctl_addr.p9050 = NULL;
 		cy_card[j].irq = (int)cy_isa_irq;
 		cy_card[j].bus_index = 0;
 		cy_card[j].first_line = cy_next_channel;
-		cy_card[j].num_chips = cy_isa_nchan / 4;
+		cy_card[j].num_chips = cy_isa_nchan / CyPORTS_PER_CHIP;
+		cy_card[j].nports = cy_isa_nchan;
 		if (cy_init_card(&cy_card[j])) {
 			cy_card[j].base_addr = NULL;
 			free_irq(cy_isa_irq, &cy_card[j]);
@@ -4781,7 +4743,7 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 	struct CUSTOM_REG __iomem *cust = base_addr;
 	struct ZFW_CTRL __iomem *pt_zfwctrl;
 	void __iomem *tmp;
-	u32 mailbox, status;
+	u32 mailbox, status, nchan;
 	unsigned int i;
 	int retval;
 
@@ -4793,7 +4755,7 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 
 	/* Check whether the firmware is already loaded and running. If
 	   positive, skip this board */
-	if (Z_FPGA_LOADED(ctl_addr) && readl(&fid->signature) == ZFIRM_ID) {
+	if (__cyz_fpga_loaded(ctl_addr) && readl(&fid->signature) == ZFIRM_ID) {
 		u32 cntval = readl(base_addr + 0x190);
 
 		udelay(100);
@@ -4812,7 +4774,7 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 
 	mailbox = readl(&ctl_addr->mail_box_0);
 
-	if (mailbox == 0 || Z_FPGA_LOADED(ctl_addr)) {
+	if (mailbox == 0 || __cyz_fpga_loaded(ctl_addr)) {
 		/* stops CPU and set window to beginning of RAM */
 		cy_writel(&ctl_addr->loc_addr_base, WIN_CREG);
 		cy_writel(&cust->cpu_stop, 0);
@@ -4828,7 +4790,7 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 				base_addr);
 		if (retval)
 			goto err_rel;
-		if (!Z_FPGA_LOADED(ctl_addr)) {
+		if (!__cyz_fpga_loaded(ctl_addr)) {
 			dev_err(&pdev->dev, "fw upload successful, but fw is "
 					"not loaded\n");
 			goto err_rel;
@@ -4887,7 +4849,7 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 				"system before loading the new FW to the "
 				"Cyclades-Z.\n");
 
-			if (Z_FPGA_LOADED(ctl_addr))
+			if (__cyz_fpga_loaded(ctl_addr))
 				plx_init(pdev, irq, ctl_addr);
 
 			retval = -EIO;
@@ -4902,16 +4864,16 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 			base_addr + ID_ADDRESS, readl(&fid->zfwctrl_addr),
 			base_addr + readl(&fid->zfwctrl_addr));
 
+	nchan = readl(&pt_zfwctrl->board_ctrl.n_channel);
 	dev_info(&pdev->dev, "Cyclades-Z FW loaded: version = %x, ports = %u\n",
-		readl(&pt_zfwctrl->board_ctrl.fw_version),
-		readl(&pt_zfwctrl->board_ctrl.n_channel));
+		readl(&pt_zfwctrl->board_ctrl.fw_version), nchan);
 
-	if (readl(&pt_zfwctrl->board_ctrl.n_channel) == 0) {
+	if (nchan == 0) {
 		dev_warn(&pdev->dev, "no Cyclades-Z ports were found. Please "
 			"check the connection between the Z host card and the "
 			"serial expanders.\n");
 
-		if (Z_FPGA_LOADED(ctl_addr))
+		if (__cyz_fpga_loaded(ctl_addr))
 			plx_init(pdev, irq, ctl_addr);
 
 		dev_info(&pdev->dev, "Null number of ports detected. Board "
@@ -4932,9 +4894,7 @@ static int __devinit cyz_load_fw(struct pci_dev *pdev, void __iomem *base_addr,
 	cy_writel(&ctl_addr->intr_ctrl_stat, readl(&ctl_addr->intr_ctrl_stat) |
 			0x00030800UL);
 
-	plx_init(pdev, irq, ctl_addr);
-
-	return 0;
+	return nchan;
 err_rel:
 	release_firmware(fw);
 err:
@@ -4946,7 +4906,7 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 {
 	void __iomem *addr0 = NULL, *addr2 = NULL;
 	char *card_name = NULL;
-	u32 mailbox;
+	u32 uninitialized_var(mailbox);
 	unsigned int device_id, nchan = 0, card_no, i;
 	unsigned char plx_ver;
 	int retval, irq;
@@ -5023,11 +4983,12 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 		}
 
 		/* Disable interrupts on the PLX before resetting it */
-		cy_writew(addr0 + 0x68, readw(addr0 + 0x68) & ~0x0900);
+		cy_writew(&ctl_addr->intr_ctrl_stat,
+				readw(&ctl_addr->intr_ctrl_stat) & ~0x0900);
 
 		plx_init(pdev, irq, addr0);
 
-		mailbox = (u32)readl(&ctl_addr->mail_box_0);
+		mailbox = readl(&ctl_addr->mail_box_0);
 
 		addr2 = ioremap_nocache(pci_resource_start(pdev, 2),
 				mailbox == ZE_V1 ? CyPCI_Ze_win : CyPCI_Zwin);
@@ -5038,12 +4999,8 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 
 		if (mailbox == ZE_V1) {
 			card_name = "Cyclades-Ze";
-
-			readl(&ctl_addr->mail_box_0);
-			nchan = ZE_V1_NPORTS;
 		} else {
 			card_name = "Cyclades-8Zo";
-
 #ifdef CY_PCI_DEBUG
 			if (mailbox == ZO_V1) {
 				cy_writel(&ctl_addr->loc_addr_base, WIN_CREG);
@@ -5065,15 +5022,12 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 			 */
 			if ((mailbox == ZO_V1) || (mailbox == ZO_V2))
 				cy_writel(addr2 + ID_ADDRESS, 0L);
-
-			retval = cyz_load_fw(pdev, addr2, addr0, irq);
-			if (retval)
-				goto err_unmap;
-			/* This must be a Cyclades-8Zo/PCI.  The extendable
-			   version will have a different device_id and will
-			   be allocated its maximum number of ports. */
-			nchan = 8;
 		}
+
+		retval = cyz_load_fw(pdev, addr2, addr0, irq);
+		if (retval <= 0)
+			goto err_unmap;
+		nchan = retval;
 	}
 
 	if ((cy_next_channel + nchan) > NR_PORTS) {
@@ -5103,8 +5057,10 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 			dev_err(&pdev->dev, "could not allocate IRQ\n");
 			goto err_unmap;
 		}
-		cy_card[card_no].num_chips = nchan / 4;
+		cy_card[card_no].num_chips = nchan / CyPORTS_PER_CHIP;
 	} else {
+		cy_card[card_no].hw_ver = mailbox;
+		cy_card[card_no].num_chips = (unsigned int)-1;
 #ifdef CONFIG_CYZ_INTR
 		/* allocate IRQ only if board has an IRQ */
 		if (irq != 0 && irq != 255) {
@@ -5117,15 +5073,15 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 			}
 		}
 #endif				/* CONFIG_CYZ_INTR */
-		cy_card[card_no].num_chips = (unsigned int)-1;
 	}
 
 	/* set cy_card */
 	cy_card[card_no].base_addr = addr2;
-	cy_card[card_no].ctl_addr = addr0;
+	cy_card[card_no].ctl_addr.p9050 = addr0;
 	cy_card[card_no].irq = irq;
 	cy_card[card_no].bus_index = 1;
 	cy_card[card_no].first_line = cy_next_channel;
+	cy_card[card_no].nports = nchan;
 	retval = cy_init_card(&cy_card[card_no]);
 	if (retval)
 		goto err_null;
@@ -5138,17 +5094,20 @@ static int __devinit cy_pci_probe(struct pci_dev *pdev,
 		plx_ver = readb(addr2 + CyPLX_VER) & 0x0f;
 		switch (plx_ver) {
 		case PLX_9050:
-
 			cy_writeb(addr0 + 0x4c, 0x43);
 			break;
 
 		case PLX_9060:
 		case PLX_9080:
 		default:	/* Old boards, use PLX_9060 */
-			plx_init(pdev, irq, addr0);
-			cy_writew(addr0 + 0x68, readw(addr0 + 0x68) | 0x0900);
+		{
+			struct RUNTIME_9060 __iomem *ctl_addr = addr0;
+			plx_init(pdev, irq, ctl_addr);
+			cy_writew(&ctl_addr->intr_ctrl_stat,
+				readw(&ctl_addr->intr_ctrl_stat) | 0x0900);
 			break;
 		}
+		}
 	}
 
 	dev_info(&pdev->dev, "%s/PCI #%d found: %d channels starting from "
@@ -5179,22 +5138,23 @@ static void __devexit cy_pci_remove(struct pci_dev *pdev)
 	unsigned int i;
 
 	/* non-Z with old PLX */
-	if (!IS_CYC_Z(*cinfo) && (readb(cinfo->base_addr + CyPLX_VER) & 0x0f) ==
+	if (!cy_is_Z(cinfo) && (readb(cinfo->base_addr + CyPLX_VER) & 0x0f) ==
 			PLX_9050)
-		cy_writeb(cinfo->ctl_addr + 0x4c, 0);
+		cy_writeb(cinfo->ctl_addr.p9050 + 0x4c, 0);
 	else
 #ifndef CONFIG_CYZ_INTR
-		if (!IS_CYC_Z(*cinfo))
+		if (!cy_is_Z(cinfo))
 #endif
-		cy_writew(cinfo->ctl_addr + 0x68,
-				readw(cinfo->ctl_addr + 0x68) & ~0x0900);
+		cy_writew(&cinfo->ctl_addr.p9060->intr_ctrl_stat,
+			readw(&cinfo->ctl_addr.p9060->intr_ctrl_stat) &
+			~0x0900);
 
 	iounmap(cinfo->base_addr);
-	if (cinfo->ctl_addr)
-		iounmap(cinfo->ctl_addr);
+	if (cinfo->ctl_addr.p9050)
+		iounmap(cinfo->ctl_addr.p9050);
 	if (cinfo->irq
 #ifndef CONFIG_CYZ_INTR
-		&& !IS_CYC_Z(*cinfo)
+		&& !cy_is_Z(cinfo)
 #endif /* CONFIG_CYZ_INTR */
 		)
 		free_irq(cinfo->irq, cinfo);
@@ -5240,7 +5200,7 @@ static int cyclades_proc_show(struct seq_file *m, void *v)
 					(cur_jifs - info->idle_stats.recv_idle)/
 					HZ, info->idle_stats.overruns,
 					/* FIXME: double check locking */
-					(long)info->port.tty->ldisc.ops->num);
+					(long)info->port.tty->ldisc->ops->num);
 			else
 				seq_printf(m, "%3d %8lu %10lu %8lu "
 					"%10lu %8lu %9lu %6ld\n",
@@ -5386,11 +5346,11 @@ static void __exit cy_cleanup_module(void)
 			/* clear interrupt */
 			cy_writeb(card->base_addr + Cy_ClrIntr, 0);
 			iounmap(card->base_addr);
-			if (card->ctl_addr)
-				iounmap(card->ctl_addr);
+			if (card->ctl_addr.p9050)
+				iounmap(card->ctl_addr.p9050);
 			if (card->irq
 #ifndef CONFIG_CYZ_INTR
-				&& !IS_CYC_Z(*card)
+				&& !cy_is_Z(card)
 #endif /* CONFIG_CYZ_INTR */
 				)
 				free_irq(card->irq, card);
diff --git a/drivers/char/epca.c b/drivers/char/epca.c
index af7c13ca9493..abef1f7d84fe 100644
--- a/drivers/char/epca.c
+++ b/drivers/char/epca.c
@@ -745,7 +745,7 @@ static int epca_carrier_raised(struct tty_port *port)
 	return 0;
 }
 
-static void epca_raise_dtr_rts(struct tty_port *port)
+static void epca_dtr_rts(struct tty_port *port, int onoff)
 {
 }
 
@@ -925,7 +925,7 @@ static const struct tty_operations pc_ops = {
 
 static const struct tty_port_operations epca_port_ops = {
 	.carrier_raised = epca_carrier_raised,
-	.raise_dtr_rts = epca_raise_dtr_rts,
+	.dtr_rts = epca_dtr_rts,
 };
 
 static int info_open(struct tty_struct *tty, struct file *filp)
@@ -1518,7 +1518,7 @@ static void doevent(int crd)
 		if (event & MODEMCHG_IND) {
 			/* A modem signal change has been indicated */
 			ch->imodem = mstat;
-			if (test_bit(ASYNC_CHECK_CD, &ch->port.flags)) {
+			if (test_bit(ASYNCB_CHECK_CD, &ch->port.flags)) {
 				/* We are now receiving dcd */
 				if (mstat & ch->dcd)
 					wake_up_interruptible(&ch->port.open_wait);
@@ -1765,9 +1765,9 @@ static void epcaparam(struct tty_struct *tty, struct channel *ch)
 		 * that the driver will wait on carrier detect.
 		 */
 		if (ts->c_cflag & CLOCAL)
-			clear_bit(ASYNC_CHECK_CD, &ch->port.flags);
+			clear_bit(ASYNCB_CHECK_CD, &ch->port.flags);
 		else
-			set_bit(ASYNC_CHECK_CD, &ch->port.flags);
+			set_bit(ASYNCB_CHECK_CD, &ch->port.flags);
 		mval = ch->m_dtr | ch->m_rts;
 	} /* End CBAUD not detected */
 	iflag = termios2digi_i(ch, ts->c_iflag);
@@ -2114,8 +2114,8 @@ static int pc_ioctl(struct tty_struct *tty, struct file *file,
 			tty_wait_until_sent(tty, 0);
 		} else {
 			/* ldisc lock already held in ioctl */
-			if (tty->ldisc.ops->flush_buffer)
-				tty->ldisc.ops->flush_buffer(tty);
+			if (tty->ldisc->ops->flush_buffer)
+				tty->ldisc->ops->flush_buffer(tty);
 		}
 		unlock_kernel();
 		/* Fall Thru */
@@ -2244,7 +2244,8 @@ static void do_softint(struct work_struct *work)
 			if (test_and_clear_bit(EPCA_EVENT_HANGUP, &ch->event)) {
 				tty_hangup(tty);
 				wake_up_interruptible(&ch->port.open_wait);
-				clear_bit(ASYNC_NORMAL_ACTIVE, &ch->port.flags);
+				clear_bit(ASYNCB_NORMAL_ACTIVE,
+						&ch->port.flags);
 			}
 		}
 		tty_kref_put(tty);
diff --git a/drivers/char/ip2/i2lib.c b/drivers/char/ip2/i2lib.c
index 0061e18aff60..0d10b89218ed 100644
--- a/drivers/char/ip2/i2lib.c
+++ b/drivers/char/ip2/i2lib.c
@@ -868,11 +868,11 @@ i2Input(i2ChanStrPtr pCh)
 		amountToMove = count;
 	}
 	// Move the first block
-	pCh->pTTY->ldisc.ops->receive_buf( pCh->pTTY,
+	pCh->pTTY->ldisc->ops->receive_buf( pCh->pTTY,
 		 &(pCh->Ibuf[stripIndex]), NULL, amountToMove );
 	// If we needed to wrap, do the second data move
 	if (count > amountToMove) {
-		pCh->pTTY->ldisc.ops->receive_buf( pCh->pTTY,
+		pCh->pTTY->ldisc->ops->receive_buf( pCh->pTTY,
 		 pCh->Ibuf, NULL, count - amountToMove );
 	}
 	// Bump and wrap the stripIndex all at once by the amount of data read. This
diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c
index afd9247cf082..517271c762e6 100644
--- a/drivers/char/ip2/ip2main.c
+++ b/drivers/char/ip2/ip2main.c
@@ -1315,8 +1315,8 @@ static inline void  isig(int sig, struct tty_struct *tty, int flush)
 	if (tty->pgrp)
 		kill_pgrp(tty->pgrp, sig, 1);
 	if (flush || !L_NOFLSH(tty)) {
-		if ( tty->ldisc.ops->flush_buffer )  
-			tty->ldisc.ops->flush_buffer(tty);
+		if ( tty->ldisc->ops->flush_buffer )  
+			tty->ldisc->ops->flush_buffer(tty);
 		i2InputFlush( tty->driver_data );
 	}
 }
diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c
index a59eac584d16..4d745a89504f 100644
--- a/drivers/char/isicom.c
+++ b/drivers/char/isicom.c
@@ -329,7 +329,7 @@ static inline void drop_rts(struct isi_port *port)
 
 /* card->lock MUST NOT be held */
 
-static void isicom_raise_dtr_rts(struct tty_port *port)
+static void isicom_dtr_rts(struct tty_port *port, int on)
 {
 	struct isi_port *ip = container_of(port, struct isi_port, port);
 	struct isi_board *card = ip->card;
@@ -339,10 +339,17 @@ static void isicom_raise_dtr_rts(struct tty_port *port)
 	if (!lock_card(card))
 		return;
 
-	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
-	outw(0x0f04, base);
-	InterruptTheCard(base);
-	ip->status |= (ISI_DTR | ISI_RTS);
+	if (on) {
+		outw(0x8000 | (channel << card->shift_count) | 0x02, base);
+		outw(0x0f04, base);
+		InterruptTheCard(base);
+		ip->status |= (ISI_DTR | ISI_RTS);
+	} else {
+		outw(0x8000 | (channel << card->shift_count) | 0x02, base);
+		outw(0x0C04, base);
+		InterruptTheCard(base);
+		ip->status &= ~(ISI_DTR | ISI_RTS);
+	}
 	unlock_card(card);
 }
 
@@ -1339,7 +1346,7 @@ static const struct tty_operations isicom_ops = {
 
 static const struct tty_port_operations isicom_port_ops = {
 	.carrier_raised		= isicom_carrier_raised,
-	.raise_dtr_rts		= isicom_raise_dtr_rts,
+	.dtr_rts		= isicom_dtr_rts,
 };
 
 static int __devinit reset_card(struct pci_dev *pdev,
diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index fff19f7e29d2..e18800c400b1 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -1140,14 +1140,14 @@ static int stli_carrier_raised(struct tty_port *port)
 	return (portp->sigs & TIOCM_CD) ? 1 : 0;
 }
 
-static void stli_raise_dtr_rts(struct tty_port *port)
+static void stli_dtr_rts(struct tty_port *port, int on)
 {
 	struct stliport *portp = container_of(port, struct stliport, port);
 	struct stlibrd *brdp = stli_brds[portp->brdnr];
-	stli_mkasysigs(&portp->asig, 1, 1);
+	stli_mkasysigs(&portp->asig, on, on);
 	if (stli_cmdwait(brdp, portp, A_SETSIGNALS, &portp->asig,
 		sizeof(asysigs_t), 0) < 0)
-			printk(KERN_WARNING "istallion: dtr raise failed.\n");
+			printk(KERN_WARNING "istallion: dtr set failed.\n");
 }
 
 
@@ -4417,7 +4417,7 @@ static const struct tty_operations stli_ops = {
 
 static const struct tty_port_operations stli_port_ops = {
 	.carrier_raised = stli_carrier_raised,
-	.raise_dtr_rts = stli_raise_dtr_rts,
+	.dtr_rts = stli_dtr_rts,
 };
 
 /*****************************************************************************/
diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 4a4cab73d0be..65b6ff2442c6 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -1184,6 +1184,11 @@ static int moxa_open(struct tty_struct *tty, struct file *filp)
 		return -ENODEV;
 	}
 
+	if (port % MAX_PORTS_PER_BOARD >= brd->numPorts) {
+		mutex_unlock(&moxa_openlock);
+		return -ENODEV;
+	}
+
 	ch = &brd->ports[port % MAX_PORTS_PER_BOARD];
 	ch->port.count++;
 	tty->driver_data = ch;
diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 13f8871e5b21..9533f43a30bb 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -547,14 +547,18 @@ static int mxser_carrier_raised(struct tty_port *port)
 	return (inb(mp->ioaddr + UART_MSR) & UART_MSR_DCD)?1:0;
 }
 
-static void mxser_raise_dtr_rts(struct tty_port *port)
+static void mxser_dtr_rts(struct tty_port *port, int on)
 {
 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
 	unsigned long flags;
 
 	spin_lock_irqsave(&mp->slock, flags);
-	outb(inb(mp->ioaddr + UART_MCR) |
-		UART_MCR_DTR | UART_MCR_RTS, mp->ioaddr + UART_MCR);
+	if (on)
+		outb(inb(mp->ioaddr + UART_MCR) |
+			UART_MCR_DTR | UART_MCR_RTS, mp->ioaddr + UART_MCR);
+	else
+		outb(inb(mp->ioaddr + UART_MCR)&~(UART_MCR_DTR | UART_MCR_RTS),
+			mp->ioaddr + UART_MCR);
 	spin_unlock_irqrestore(&mp->slock, flags);
 }
 
@@ -2356,7 +2360,7 @@ static const struct tty_operations mxser_ops = {
 
 struct tty_port_operations mxser_port_ops = {
 	.carrier_raised = mxser_carrier_raised,
-	.raise_dtr_rts = mxser_raise_dtr_rts,
+	.dtr_rts = mxser_dtr_rts,
 };
 
 /*
diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index bacb3e2872ae..461ece591a5b 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -342,8 +342,8 @@ static int n_hdlc_tty_open (struct tty_struct *tty)
 #endif
 	
 	/* Flush any pending characters in the driver and discipline. */
-	if (tty->ldisc.ops->flush_buffer)
-		tty->ldisc.ops->flush_buffer(tty);
+	if (tty->ldisc->ops->flush_buffer)
+		tty->ldisc->ops->flush_buffer(tty);
 
 	tty_driver_flush_buffer(tty);
 		
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index f6f0e4ec2b51..94a5d5020abc 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -73,24 +73,6 @@
 #define ECHO_OP_SET_CANON_COL 0x81
 #define ECHO_OP_ERASE_TAB 0x82
 
-static inline unsigned char *alloc_buf(void)
-{
-	gfp_t prio = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
-
-	if (PAGE_SIZE != N_TTY_BUF_SIZE)
-		return kmalloc(N_TTY_BUF_SIZE, prio);
-	else
-		return (unsigned char *)__get_free_page(prio);
-}
-
-static inline void free_buf(unsigned char *buf)
-{
-	if (PAGE_SIZE != N_TTY_BUF_SIZE)
-		kfree(buf);
-	else
-		free_page((unsigned long) buf);
-}
-
 static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
 			       unsigned char __user *ptr)
 {
@@ -1558,11 +1540,11 @@ static void n_tty_close(struct tty_struct *tty)
 {
 	n_tty_flush_buffer(tty);
 	if (tty->read_buf) {
-		free_buf(tty->read_buf);
+		kfree(tty->read_buf);
 		tty->read_buf = NULL;
 	}
 	if (tty->echo_buf) {
-		free_buf(tty->echo_buf);
+		kfree(tty->echo_buf);
 		tty->echo_buf = NULL;
 	}
 }
@@ -1584,17 +1566,16 @@ static int n_tty_open(struct tty_struct *tty)
 
 	/* These are ugly. Currently a malloc failure here can panic */
 	if (!tty->read_buf) {
-		tty->read_buf = alloc_buf();
+		tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
 		if (!tty->read_buf)
 			return -ENOMEM;
 	}
 	if (!tty->echo_buf) {
-		tty->echo_buf = alloc_buf();
+		tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+
 		if (!tty->echo_buf)
 			return -ENOMEM;
 	}
-	memset(tty->read_buf, 0, N_TTY_BUF_SIZE);
-	memset(tty->echo_buf, 0, N_TTY_BUF_SIZE);
 	reset_buffer_flags(tty);
 	tty->column = 0;
 	n_tty_set_termios(tty, NULL);
diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index 19d79fc54461..77b364889224 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -383,7 +383,7 @@ static void async_mode(MGSLPC_INFO *info);
 static void tx_timeout(unsigned long context);
 
 static int carrier_raised(struct tty_port *port);
-static void raise_dtr_rts(struct tty_port *port);
+static void dtr_rts(struct tty_port *port, int onoff);
 
 #if SYNCLINK_GENERIC_HDLC
 #define dev_to_port(D) (dev_to_hdlc(D)->priv)
@@ -513,7 +513,7 @@ static void ldisc_receive_buf(struct tty_struct *tty,
 
 static const struct tty_port_operations mgslpc_port_ops = {
 	.carrier_raised = carrier_raised,
-	.raise_dtr_rts = raise_dtr_rts
+	.dtr_rts = dtr_rts
 };
 
 static int mgslpc_probe(struct pcmcia_device *link)
@@ -2528,13 +2528,16 @@ static int carrier_raised(struct tty_port *port)
 	return 0;
 }
 
-static void raise_dtr_rts(struct tty_port *port)
+static void dtr_rts(struct tty_port *port, int onoff)
 {
 	MGSLPC_INFO *info = container_of(port, MGSLPC_INFO, port);
 	unsigned long flags;
 
 	spin_lock_irqsave(&info->lock,flags);
-	info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+	if (onoff)
+		info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+	else
+		info->serial_signals &= ~SerialSignal_RTS + SerialSignal_DTR;
 	set_signals(info);
 	spin_unlock_irqrestore(&info->lock,flags);
 }
diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 31038a0052a2..5acd29e6e043 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -30,7 +30,6 @@
 
 #include <asm/system.h>
 
-/* These are global because they are accessed in tty_io.c */
 #ifdef CONFIG_UNIX98_PTYS
 static struct tty_driver *ptm_driver;
 static struct tty_driver *pts_driver;
@@ -111,7 +110,7 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf,
 	c = to->receive_room;
 	if (c > count)
 		c = count;
-	to->ldisc.ops->receive_buf(to, buf, NULL, c);
+	to->ldisc->ops->receive_buf(to, buf, NULL, c);
 
 	return c;
 }
@@ -149,11 +148,11 @@ static int pty_chars_in_buffer(struct tty_struct *tty)
 	int count;
 
 	/* We should get the line discipline lock for "tty->link" */
-	if (!to || !to->ldisc.ops->chars_in_buffer)
+	if (!to || !to->ldisc->ops->chars_in_buffer)
 		return 0;
 
 	/* The ldisc must report 0 if no characters available to be read */
-	count = to->ldisc.ops->chars_in_buffer(to);
+	count = to->ldisc->ops->chars_in_buffer(to);
 
 	if (tty->driver->subtype == PTY_TYPE_SLAVE)
 		return count;
@@ -187,8 +186,8 @@ static void pty_flush_buffer(struct tty_struct *tty)
 	if (!to)
 		return;
 
-	if (to->ldisc.ops->flush_buffer)
-		to->ldisc.ops->flush_buffer(to);
+	if (to->ldisc->ops->flush_buffer)
+		to->ldisc->ops->flush_buffer(to);
 
 	if (to->packet) {
 		spin_lock_irqsave(&tty->ctrl_lock, flags);
diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index f59fc5cea067..63d5b628477a 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -872,11 +872,16 @@ static int carrier_raised(struct tty_port *port)
 	return (sGetChanStatusLo(&info->channel) & CD_ACT) ? 1 : 0;
 }
 
-static void raise_dtr_rts(struct tty_port *port)
+static void dtr_rts(struct tty_port *port, int on)
 {
 	struct r_port *info = container_of(port, struct r_port, port);
-	sSetDTR(&info->channel);
-	sSetRTS(&info->channel);
+	if (on) {
+		sSetDTR(&info->channel);
+		sSetRTS(&info->channel);
+	} else {
+		sClrDTR(&info->channel);
+		sClrRTS(&info->channel);
+	}
 }
 
 /*
@@ -934,7 +939,7 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
 	/*
 	 * Info->count is now 1; so it's safe to sleep now.
 	 */
-	if (!test_bit(ASYNC_INITIALIZED, &port->flags)) {
+	if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
 		cp = &info->channel;
 		sSetRxTrigger(cp, TRIG_1);
 		if (sGetChanStatus(cp) & CD_ACT)
@@ -958,7 +963,7 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
 		sEnRxFIFO(cp);
 		sEnTransmit(cp);
 
-		set_bit(ASYNC_INITIALIZED, &info->port.flags);
+		set_bit(ASYNCB_INITIALIZED, &info->port.flags);
 
 		/*
 		 * Set up the tty->alt_speed kludge
@@ -1641,7 +1646,7 @@ static int rp_write(struct tty_struct *tty,
 	/*  Write remaining data into the port's xmit_buf */
 	while (1) {
 		/* Hung up ? */
-		if (!test_bit(ASYNC_NORMAL_ACTIVE, &info->port.flags))
+		if (!test_bit(ASYNCB_NORMAL_ACTIVE, &info->port.flags))
 			goto end;
 		c = min(count, XMIT_BUF_SIZE - info->xmit_cnt - 1);
 		c = min(c, XMIT_BUF_SIZE - info->xmit_head);
@@ -2250,7 +2255,7 @@ static const struct tty_operations rocket_ops = {
 
 static const struct tty_port_operations rocket_port_ops = {
 	.carrier_raised = carrier_raised,
-	.raise_dtr_rts = raise_dtr_rts,
+	.dtr_rts = dtr_rts,
 };
 
 /*
diff --git a/drivers/char/selection.c b/drivers/char/selection.c
index cb8ca5698963..f97b9e848064 100644
--- a/drivers/char/selection.c
+++ b/drivers/char/selection.c
@@ -327,7 +327,7 @@ int paste_selection(struct tty_struct *tty)
 		}
 		count = sel_buffer_lth - pasted;
 		count = min(count, tty->receive_room);
-		tty->ldisc.ops->receive_buf(tty, sel_buffer + pasted,
+		tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
 								NULL, count);
 		pasted += count;
 	}
diff --git a/drivers/char/stallion.c b/drivers/char/stallion.c
index 2ad813a801dc..53e504f41b20 100644
--- a/drivers/char/stallion.c
+++ b/drivers/char/stallion.c
@@ -772,11 +772,11 @@ static int stl_carrier_raised(struct tty_port *port)
 	return (portp->sigs & TIOCM_CD) ? 1 : 0;
 }
 
-static void stl_raise_dtr_rts(struct tty_port *port)
+static void stl_dtr_rts(struct tty_port *port, int on)
 {
 	struct stlport *portp = container_of(port, struct stlport, port);
 	/* Takes brd_lock internally */
-	stl_setsignals(portp, 1, 1);
+	stl_setsignals(portp, on, on);
 }
 
 /*****************************************************************************/
@@ -2547,7 +2547,7 @@ static const struct tty_operations stl_ops = {
 
 static const struct tty_port_operations stl_port_ops = {
 	.carrier_raised = stl_carrier_raised,
-	.raise_dtr_rts = stl_raise_dtr_rts,
+	.dtr_rts = stl_dtr_rts,
 };
 
 /*****************************************************************************/
diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
index afd0b26ca056..afded3a2379c 100644
--- a/drivers/char/synclink.c
+++ b/drivers/char/synclink.c
@@ -3247,13 +3247,16 @@ static int carrier_raised(struct tty_port *port)
 	return (info->serial_signals & SerialSignal_DCD) ? 1 : 0;
 }
 
-static void raise_dtr_rts(struct tty_port *port)
+static void dtr_rts(struct tty_port *port, int on)
 {
 	struct mgsl_struct *info = container_of(port, struct mgsl_struct, port);
 	unsigned long flags;
 
 	spin_lock_irqsave(&info->irq_spinlock,flags);
-	info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+	if (on)
+		info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+	else
+		info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
  	usc_set_serial_signals(info);
 	spin_unlock_irqrestore(&info->irq_spinlock,flags);
 }
@@ -4258,7 +4261,7 @@ static void mgsl_add_device( struct mgsl_struct *info )
 
 static const struct tty_port_operations mgsl_port_ops = {
 	.carrier_raised = carrier_raised,
-	.raise_dtr_rts = raise_dtr_rts,
+	.dtr_rts = dtr_rts,
 };
 
 
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 5e256494686a..1386625fc4ca 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -214,6 +214,7 @@ struct slgt_desc
 #define set_desc_next(a,b) (a).next   = cpu_to_le32((unsigned int)(b))
 #define set_desc_count(a,b)(a).count  = cpu_to_le16((unsigned short)(b))
 #define set_desc_eof(a,b)  (a).status = cpu_to_le16((b) ? (le16_to_cpu((a).status) | BIT0) : (le16_to_cpu((a).status) & ~BIT0))
+#define set_desc_status(a, b) (a).status = cpu_to_le16((unsigned short)(b))
 #define desc_count(a)      (le16_to_cpu((a).count))
 #define desc_status(a)     (le16_to_cpu((a).status))
 #define desc_complete(a)   (le16_to_cpu((a).status) & BIT15)
@@ -297,6 +298,7 @@ struct slgt_info {
 	u32 max_frame_size;       /* as set by device config */
 
 	unsigned int rbuf_fill_level;
+	unsigned int rx_pio;
 	unsigned int if_mode;
 	unsigned int base_clock;
 
@@ -331,6 +333,8 @@ struct slgt_info {
 	struct slgt_desc *rbufs;
 	unsigned int rbuf_current;
 	unsigned int rbuf_index;
+	unsigned int rbuf_fill_index;
+	unsigned short rbuf_fill_count;
 
 	unsigned int tbuf_count;
 	struct slgt_desc *tbufs;
@@ -2110,6 +2114,40 @@ static void ri_change(struct slgt_info *info, unsigned short status)
 	info->pending_bh |= BH_STATUS;
 }
 
+static void isr_rxdata(struct slgt_info *info)
+{
+	unsigned int count = info->rbuf_fill_count;
+	unsigned int i = info->rbuf_fill_index;
+	unsigned short reg;
+
+	while (rd_reg16(info, SSR) & IRQ_RXDATA) {
+		reg = rd_reg16(info, RDR);
+		DBGISR(("isr_rxdata %s RDR=%04X\n", info->device_name, reg));
+		if (desc_complete(info->rbufs[i])) {
+			/* all buffers full */
+			rx_stop(info);
+			info->rx_restart = 1;
+			continue;
+		}
+		info->rbufs[i].buf[count++] = (unsigned char)reg;
+		/* async mode saves status byte to buffer for each data byte */
+		if (info->params.mode == MGSL_MODE_ASYNC)
+			info->rbufs[i].buf[count++] = (unsigned char)(reg >> 8);
+		if (count == info->rbuf_fill_level || (reg & BIT10)) {
+			/* buffer full or end of frame */
+			set_desc_count(info->rbufs[i], count);
+			set_desc_status(info->rbufs[i], BIT15 | (reg >> 8));
+			info->rbuf_fill_count = count = 0;
+			if (++i == info->rbuf_count)
+				i = 0;
+			info->pending_bh |= BH_RECEIVE;
+		}
+	}
+
+	info->rbuf_fill_index = i;
+	info->rbuf_fill_count = count;
+}
+
 static void isr_serial(struct slgt_info *info)
 {
 	unsigned short status = rd_reg16(info, SSR);
@@ -2125,6 +2163,8 @@ static void isr_serial(struct slgt_info *info)
 			if (info->tx_count)
 				isr_txeom(info, status);
 		}
+		if (info->rx_pio && (status & IRQ_RXDATA))
+			isr_rxdata(info);
 		if ((status & IRQ_RXBREAK) && (status & RXBREAK)) {
 			info->icount.brk++;
 			/* process break detection if tty control allows */
@@ -2141,7 +2181,8 @@ static void isr_serial(struct slgt_info *info)
 	} else {
 		if (status & (IRQ_TXIDLE + IRQ_TXUNDER))
 			isr_txeom(info, status);
-
+		if (info->rx_pio && (status & IRQ_RXDATA))
+			isr_rxdata(info);
 		if (status & IRQ_RXIDLE) {
 			if (status & RXIDLE)
 				info->icount.rxidle++;
@@ -2642,6 +2683,10 @@ static int rx_enable(struct slgt_info *info, int enable)
 			return -EINVAL;
 		}
 		info->rbuf_fill_level = rbuf_fill_level;
+		if (rbuf_fill_level < 128)
+			info->rx_pio = 1; /* PIO mode */
+		else
+			info->rx_pio = 0; /* DMA mode */
 		rx_stop(info); /* restart receiver to use new fill level */
 	}
 
@@ -3099,13 +3144,16 @@ static int carrier_raised(struct tty_port *port)
 	return (info->signals & SerialSignal_DCD) ? 1 : 0;
 }
 
-static void raise_dtr_rts(struct tty_port *port)
+static void dtr_rts(struct tty_port *port, int on)
 {
 	unsigned long flags;
 	struct slgt_info *info = container_of(port, struct slgt_info, port);
 
 	spin_lock_irqsave(&info->lock,flags);
-	info->signals |= SerialSignal_RTS + SerialSignal_DTR;
+	if (on)
+		info->signals |= SerialSignal_RTS + SerialSignal_DTR;
+	else
+		info->signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
  	set_signals(info);
 	spin_unlock_irqrestore(&info->lock,flags);
 }
@@ -3419,7 +3467,7 @@ static void add_device(struct slgt_info *info)
 
 static const struct tty_port_operations slgt_port_ops = {
 	.carrier_raised = carrier_raised,
-	.raise_dtr_rts = raise_dtr_rts,
+	.dtr_rts = dtr_rts,
 };
 
 /*
@@ -3841,15 +3889,27 @@ static void rx_start(struct slgt_info *info)
 	rdma_reset(info);
 	reset_rbufs(info);
 
-	/* set 1st descriptor address */
-	wr_reg32(info, RDDAR, info->rbufs[0].pdesc);
-
-	if (info->params.mode != MGSL_MODE_ASYNC) {
-		/* enable rx DMA and DMA interrupt */
-		wr_reg32(info, RDCSR, (BIT2 + BIT0));
+	if (info->rx_pio) {
+		/* rx request when rx FIFO not empty */
+		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) & ~BIT14));
+		slgt_irq_on(info, IRQ_RXDATA);
+		if (info->params.mode == MGSL_MODE_ASYNC) {
+			/* enable saving of rx status */
+			wr_reg32(info, RDCSR, BIT6);
+		}
 	} else {
-		/* enable saving of rx status, rx DMA and DMA interrupt */
-		wr_reg32(info, RDCSR, (BIT6 + BIT2 + BIT0));
+		/* rx request when rx FIFO half full */
+		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT14));
+		/* set 1st descriptor address */
+		wr_reg32(info, RDDAR, info->rbufs[0].pdesc);
+
+		if (info->params.mode != MGSL_MODE_ASYNC) {
+			/* enable rx DMA and DMA interrupt */
+			wr_reg32(info, RDCSR, (BIT2 + BIT0));
+		} else {
+			/* enable saving of rx status, rx DMA and DMA interrupt */
+			wr_reg32(info, RDCSR, (BIT6 + BIT2 + BIT0));
+		}
 	}
 
 	slgt_irq_on(info, IRQ_RXOVER);
@@ -4467,6 +4527,8 @@ static void free_rbufs(struct slgt_info *info, unsigned int i, unsigned int last
 static void reset_rbufs(struct slgt_info *info)
 {
 	free_rbufs(info, 0, info->rbuf_count - 1);
+	info->rbuf_fill_index = 0;
+	info->rbuf_fill_count = 0;
 }
 
 /*
diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index 26de60efe4b2..6f727e3c53ad 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -3277,13 +3277,16 @@ static int carrier_raised(struct tty_port *port)
 	return (info->serial_signals & SerialSignal_DCD) ? 1 : 0;
 }
 
-static void raise_dtr_rts(struct tty_port *port)
+static void dtr_rts(struct tty_port *port, int on)
 {
 	SLMP_INFO *info = container_of(port, SLMP_INFO, port);
 	unsigned long flags;
 
 	spin_lock_irqsave(&info->lock,flags);
-	info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+	if (on)
+		info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+	else
+		info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
  	set_signals(info);
 	spin_unlock_irqrestore(&info->lock,flags);
 }
@@ -3746,7 +3749,7 @@ static void add_device(SLMP_INFO *info)
 
 static const struct tty_port_operations port_ops = {
 	.carrier_raised = carrier_raised,
-	.raise_dtr_rts = raise_dtr_rts,
+	.dtr_rts = dtr_rts,
 };
 
 /* Allocate and initialize a device instance structure
diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c
index 55ba6f142883..ac16fbec72d0 100644
--- a/drivers/char/tty_audit.c
+++ b/drivers/char/tty_audit.c
@@ -29,10 +29,7 @@ static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
 	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
 	if (!buf)
 		goto err;
-	if (PAGE_SIZE != N_TTY_BUF_SIZE)
-		buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
-	else
-		buf->data = (unsigned char *)__get_free_page(GFP_KERNEL);
+	buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
 	if (!buf->data)
 		goto err_buf;
 	atomic_set(&buf->count, 1);
@@ -52,10 +49,7 @@ err:
 static void tty_audit_buf_free(struct tty_audit_buf *buf)
 {
 	WARN_ON(buf->valid != 0);
-	if (PAGE_SIZE != N_TTY_BUF_SIZE)
-		kfree(buf->data);
-	else
-		free_page((unsigned long)buf->data);
+	kfree(buf->data);
 	kfree(buf);
 }
 
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 66b99a2049e3..939e198d7670 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -295,7 +295,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 	struct tty_driver *p, *res = NULL;
 	int tty_line = 0;
 	int len;
-	char *str;
+	char *str, *stp;
 
 	for (str = name; *str; str++)
 		if ((*str >= '0' && *str <= '9') || *str == ',')
@@ -311,13 +311,14 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 	list_for_each_entry(p, &tty_drivers, tty_drivers) {
 		if (strncmp(name, p->name, len) != 0)
 			continue;
-		if (*str == ',')
-			str++;
-		if (*str == '\0')
-			str = NULL;
+		stp = str;
+		if (*stp == ',')
+			stp++;
+		if (*stp == '\0')
+			stp = NULL;
 
 		if (tty_line >= 0 && tty_line <= p->num && p->ops &&
-		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) {
+		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
 			res = tty_driver_kref_get(p);
 			*line = tty_line;
 			break;
@@ -470,43 +471,6 @@ void tty_wakeup(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_wakeup);
 
 /**
- *	tty_ldisc_flush	-	flush line discipline queue
- *	@tty: tty
- *
- *	Flush the line discipline queue (if any) for this tty. If there
- *	is no line discipline active this is a no-op.
- */
-
-void tty_ldisc_flush(struct tty_struct *tty)
-{
-	struct tty_ldisc *ld = tty_ldisc_ref(tty);
-	if (ld) {
-		if (ld->ops->flush_buffer)
-			ld->ops->flush_buffer(tty);
-		tty_ldisc_deref(ld);
-	}
-	tty_buffer_flush(tty);
-}
-
-EXPORT_SYMBOL_GPL(tty_ldisc_flush);
-
-/**
- *	tty_reset_termios	-	reset terminal state
- *	@tty: tty to reset
- *
- *	Restore a terminal to the driver default state
- */
-
-static void tty_reset_termios(struct tty_struct *tty)
-{
-	mutex_lock(&tty->termios_mutex);
-	*tty->termios = tty->driver->init_termios;
-	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
-	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
-	mutex_unlock(&tty->termios_mutex);
-}
-
-/**
  *	do_tty_hangup		-	actual handler for hangup events
  *	@work: tty device
  *
@@ -535,7 +499,6 @@ static void do_tty_hangup(struct work_struct *work)
 	struct file *cons_filp = NULL;
 	struct file *filp, *f = NULL;
 	struct task_struct *p;
-	struct tty_ldisc *ld;
 	int    closecount = 0, n;
 	unsigned long flags;
 	int refs = 0;
@@ -566,40 +529,8 @@ static void do_tty_hangup(struct work_struct *work)
 		filp->f_op = &hung_up_tty_fops;
 	}
 	file_list_unlock();
-	/*
-	 * FIXME! What are the locking issues here? This may me overdoing
-	 * things... This question is especially important now that we've
-	 * removed the irqlock.
-	 */
-	ld = tty_ldisc_ref(tty);
-	if (ld != NULL) {
-		/* We may have no line discipline at this point */
-		if (ld->ops->flush_buffer)
-			ld->ops->flush_buffer(tty);
-		tty_driver_flush_buffer(tty);
-		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
-		    ld->ops->write_wakeup)
-			ld->ops->write_wakeup(tty);
-		if (ld->ops->hangup)
-			ld->ops->hangup(tty);
-	}
-	/*
-	 * FIXME: Once we trust the LDISC code better we can wait here for
-	 * ldisc completion and fix the driver call race
-	 */
-	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
-	wake_up_interruptible_poll(&tty->read_wait, POLLIN);
-	/*
-	 * Shutdown the current line discipline, and reset it to
-	 * N_TTY.
-	 */
-	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
-		tty_reset_termios(tty);
-	/* Defer ldisc switch */
-	/* tty_deferred_ldisc_switch(N_TTY);
 
-	  This should get done automatically when the port closes and
-	  tty_release is called */
+	tty_ldisc_hangup(tty);
 
 	read_lock(&tasklist_lock);
 	if (tty->session) {
@@ -628,12 +559,15 @@ static void do_tty_hangup(struct work_struct *work)
 	read_unlock(&tasklist_lock);
 
 	spin_lock_irqsave(&tty->ctrl_lock, flags);
-	tty->flags = 0;
+	clear_bit(TTY_THROTTLED, &tty->flags);
+	clear_bit(TTY_PUSH, &tty->flags);
+	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 	put_pid(tty->session);
 	put_pid(tty->pgrp);
 	tty->session = NULL;
 	tty->pgrp = NULL;
 	tty->ctrl_status = 0;
+	set_bit(TTY_HUPPED, &tty->flags);
 	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 
 	/* Account for the p->signal references we killed */
@@ -659,10 +593,7 @@ static void do_tty_hangup(struct work_struct *work)
 	 * can't yet guarantee all that.
 	 */
 	set_bit(TTY_HUPPED, &tty->flags);
-	if (ld) {
-		tty_ldisc_enable(tty);
-		tty_ldisc_deref(ld);
-	}
+	tty_ldisc_enable(tty);
 	unlock_kernel();
 	if (f)
 		fput(f);
@@ -2480,6 +2411,24 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
 	return tty->ops->tiocmset(tty, file, set, clear);
 }
 
+struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+{
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		tty = tty->link;
+	return tty;
+}
+EXPORT_SYMBOL(tty_pair_get_tty);
+
+struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
+{
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+	    return tty;
+	return tty->link;
+}
+EXPORT_SYMBOL(tty_pair_get_pty);
+
 /*
  * Split this up, as gcc can choke on it otherwise..
  */
@@ -2495,11 +2444,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
 		return -EINVAL;
 
-	real_tty = tty;
-	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
-	    tty->driver->subtype == PTY_TYPE_MASTER)
-		real_tty = tty->link;
-
+	real_tty = tty_pair_get_tty(tty);
 
 	/*
 	 * Factor out some common prep work
@@ -2555,7 +2500,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case TIOCGSID:
 		return tiocgsid(tty, real_tty, p);
 	case TIOCGETD:
-		return put_user(tty->ldisc.ops->num, (int __user *)p);
+		return put_user(tty->ldisc->ops->num, (int __user *)p);
 	case TIOCSETD:
 		return tiocsetd(tty, p);
 	/*
@@ -2770,6 +2715,7 @@ void initialize_tty_struct(struct tty_struct *tty,
 	tty->buf.head = tty->buf.tail = NULL;
 	tty_buffer_init(tty);
 	mutex_init(&tty->termios_mutex);
+	mutex_init(&tty->ldisc_mutex);
 	init_waitqueue_head(&tty->write_wait);
 	init_waitqueue_head(&tty->read_wait);
 	INIT_WORK(&tty->hangup_work, do_tty_hangup);
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 6f4c7d0a53bf..8116bb1c8f80 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -97,14 +97,19 @@ EXPORT_SYMBOL(tty_driver_flush_buffer);
  *	@tty: terminal
  *
  *	Indicate that a tty should stop transmitting data down the stack.
+ *	Takes the termios mutex to protect against parallel throttle/unthrottle
+ *	and also to ensure the driver can consistently reference its own
+ *	termios data at this point when implementing software flow control.
  */
 
 void tty_throttle(struct tty_struct *tty)
 {
+	mutex_lock(&tty->termios_mutex);
 	/* check TTY_THROTTLED first so it indicates our state */
 	if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
 	    tty->ops->throttle)
 		tty->ops->throttle(tty);
+	mutex_unlock(&tty->termios_mutex);
 }
 EXPORT_SYMBOL(tty_throttle);
 
@@ -113,13 +118,21 @@ EXPORT_SYMBOL(tty_throttle);
  *	@tty: terminal
  *
  *	Indicate that a tty may continue transmitting data down the stack.
+ *	Takes the termios mutex to protect against parallel throttle/unthrottle
+ *	and also to ensure the driver can consistently reference its own
+ *	termios data at this point when implementing software flow control.
+ *
+ *	Drivers should however remember that the stack can issue a throttle,
+ *	then change flow control method, then unthrottle.
  */
 
 void tty_unthrottle(struct tty_struct *tty)
 {
+	mutex_lock(&tty->termios_mutex);
 	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
 	    tty->ops->unthrottle)
 		tty->ops->unthrottle(tty);
+	mutex_unlock(&tty->termios_mutex);
 }
 EXPORT_SYMBOL(tty_unthrottle);
 
@@ -613,9 +626,25 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
 	return 0;
 }
 
+static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
+{
+	mutex_lock(&tty->termios_mutex);
+	memcpy(kterm, tty->termios, sizeof(struct ktermios));
+	mutex_unlock(&tty->termios_mutex);
+}
+
+static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
+{
+	mutex_lock(&tty->termios_mutex);
+	memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
+	mutex_unlock(&tty->termios_mutex);
+}
+
 static int get_termio(struct tty_struct *tty, struct termio __user *termio)
 {
-	if (kernel_termios_to_user_termio(termio, tty->termios))
+	struct ktermios kterm;
+	copy_termios(tty, &kterm);
+	if (kernel_termios_to_user_termio(termio, &kterm))
 		return -EFAULT;
 	return 0;
 }
@@ -917,6 +946,8 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 	struct tty_struct *real_tty;
 	void __user *p = (void __user *)arg;
 	int ret = 0;
+	struct ktermios kterm;
+	struct termiox ktermx;
 
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 	    tty->driver->subtype == PTY_TYPE_MASTER)
@@ -952,23 +983,20 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 		return set_termios(real_tty, p, TERMIOS_OLD);
 #ifndef TCGETS2
 	case TCGETS:
-		mutex_lock(&real_tty->termios_mutex);
-		if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
 			ret = -EFAULT;
-		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 #else
 	case TCGETS:
-		mutex_lock(&real_tty->termios_mutex);
-		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
 			ret = -EFAULT;
-		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 	case TCGETS2:
-		mutex_lock(&real_tty->termios_mutex);
-		if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
 			ret = -EFAULT;
-		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 	case TCSETSF2:
 		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
@@ -987,34 +1015,36 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 		return set_termios(real_tty, p, TERMIOS_TERMIO);
 #ifndef TCGETS2
 	case TIOCGLCKTRMIOS:
-		mutex_lock(&real_tty->termios_mutex);
-		if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
+		copy_termios_locked(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
 			ret = -EFAULT;
-		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 	case TIOCSLCKTRMIOS:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
-		mutex_lock(&real_tty->termios_mutex);
-		if (user_termios_to_kernel_termios(real_tty->termios_locked,
+		copy_termios_locked(real_tty, &kterm);
+		if (user_termios_to_kernel_termios(&kterm,
 					       (struct termios __user *) arg))
-			ret = -EFAULT;
+			return -EFAULT;
+		mutex_lock(&real_tty->termios_mutex);
+		memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
 		mutex_unlock(&real_tty->termios_mutex);
-		return ret;
+		return 0;
 #else
 	case TIOCGLCKTRMIOS:
-		mutex_lock(&real_tty->termios_mutex);
-		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))
+		copy_termios_locked(real_tty, &kterm);
+		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
 			ret = -EFAULT;
-		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 	case TIOCSLCKTRMIOS:
 		if (!capable(CAP_SYS_ADMIN))
-			ret = -EPERM;
-		mutex_lock(&real_tty->termios_mutex);
-		if (user_termios_to_kernel_termios_1(real_tty->termios_locked,
+			return -EPERM;
+		copy_termios_locked(real_tty, &kterm);
+		if (user_termios_to_kernel_termios_1(&kterm,
 					       (struct termios __user *) arg))
-			ret = -EFAULT;
+			return -EFAULT;
+		mutex_lock(&real_tty->termios_mutex);
+		memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
 		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 #endif
@@ -1023,9 +1053,10 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 		if (real_tty->termiox == NULL)
 			return -EINVAL;
 		mutex_lock(&real_tty->termios_mutex);
-		if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))
-			ret = -EFAULT;
+		memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
 		mutex_unlock(&real_tty->termios_mutex);
+		if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
+			ret = -EFAULT;
 		return ret;
 	case TCSETX:
 		return set_termiox(real_tty, p, 0);
@@ -1035,10 +1066,9 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 		return set_termiox(real_tty, p, TERMIOS_FLUSH);
 #endif		
 	case TIOCGSOFTCAR:
-		mutex_lock(&real_tty->termios_mutex);
-		ret = put_user(C_CLOCAL(real_tty) ? 1 : 0,
+		copy_termios(real_tty, &kterm);
+		ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
 						(int __user *)arg);
-		mutex_unlock(&real_tty->termios_mutex);
 		return ret;
 	case TIOCSSOFTCAR:
 		if (get_user(arg, (unsigned int __user *) arg))
diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c
index f78f5b0127a8..39c8f86dedd4 100644
--- a/drivers/char/tty_ldisc.c
+++ b/drivers/char/tty_ldisc.c
@@ -115,19 +115,22 @@ EXPORT_SYMBOL(tty_unregister_ldisc);
 /**
  *	tty_ldisc_try_get	-	try and reference an ldisc
  *	@disc: ldisc number
- *	@ld: tty ldisc structure to complete
  *
  *	Attempt to open and lock a line discipline into place. Return
- *	the line discipline refcounted and assigned in ld. On an error
- *	report the error code back
+ *	the line discipline refcounted or an error.
  */
 
-static int tty_ldisc_try_get(int disc, struct tty_ldisc *ld)
+static struct tty_ldisc *tty_ldisc_try_get(int disc)
 {
 	unsigned long flags;
+	struct tty_ldisc *ld;
 	struct tty_ldisc_ops *ldops;
 	int err = -EINVAL;
-	
+
+	ld = kmalloc(sizeof(struct tty_ldisc), GFP_KERNEL);
+	if (ld == NULL)
+		return ERR_PTR(-ENOMEM);
+
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
 	ld->ops = NULL;
 	ldops = tty_ldiscs[disc];
@@ -140,17 +143,19 @@ static int tty_ldisc_try_get(int disc, struct tty_ldisc *ld)
 			/* lock it */
 			ldops->refcount++;
 			ld->ops = ldops;
+			ld->refcount = 0;
 			err = 0;
 		}
 	}
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-	return err;
+	if (err)
+		return ERR_PTR(err);
+	return ld;
 }
 
 /**
  *	tty_ldisc_get		-	take a reference to an ldisc
  *	@disc: ldisc number
- *	@ld: tty line discipline structure to use
  *
  *	Takes a reference to a line discipline. Deals with refcounts and
  *	module locking counts. Returns NULL if the discipline is not available.
@@ -161,52 +166,54 @@ static int tty_ldisc_try_get(int disc, struct tty_ldisc *ld)
  *		takes tty_ldisc_lock to guard against ldisc races
  */
 
-static int tty_ldisc_get(int disc, struct tty_ldisc *ld)
+static struct tty_ldisc *tty_ldisc_get(int disc)
 {
-	int err;
+	struct tty_ldisc *ld;
 
 	if (disc < N_TTY || disc >= NR_LDISCS)
-		return -EINVAL;
-	err = tty_ldisc_try_get(disc, ld);
-	if (err < 0) {
+		return ERR_PTR(-EINVAL);
+	ld = tty_ldisc_try_get(disc);
+	if (IS_ERR(ld)) {
 		request_module("tty-ldisc-%d", disc);
-		err = tty_ldisc_try_get(disc, ld);
+		ld = tty_ldisc_try_get(disc);
 	}
-	return err;
+	return ld;
 }
 
 /**
  *	tty_ldisc_put		-	drop ldisc reference
- *	@disc: ldisc number
+ *	@ld: ldisc
  *
  *	Drop a reference to a line discipline. Manage refcounts and
- *	module usage counts
+ *	module usage counts. Free the ldisc once the recount hits zero.
  *
  *	Locking:
  *		takes tty_ldisc_lock to guard against ldisc races
  */
 
-static void tty_ldisc_put(struct tty_ldisc_ops *ld)
+static void tty_ldisc_put(struct tty_ldisc *ld)
 {
 	unsigned long flags;
-	int disc = ld->num;
+	int disc = ld->ops->num;
+	struct tty_ldisc_ops *ldo;
 
 	BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
 
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	ld = tty_ldiscs[disc];
-	BUG_ON(ld->refcount == 0);
-	ld->refcount--;
-	module_put(ld->owner);
+	ldo = tty_ldiscs[disc];
+	BUG_ON(ldo->refcount == 0);
+	ldo->refcount--;
+	module_put(ldo->owner);
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	kfree(ld);
 }
 
-static void * tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
+static void *tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
 {
 	return (*pos < NR_LDISCS) ? pos : NULL;
 }
 
-static void * tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
+static void *tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	(*pos)++;
 	return (*pos < NR_LDISCS) ? pos : NULL;
@@ -219,12 +226,13 @@ static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
 static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
 {
 	int i = *(loff_t *)v;
-	struct tty_ldisc ld;
-	
-	if (tty_ldisc_get(i, &ld) < 0)
+	struct tty_ldisc *ld;
+
+	ld = tty_ldisc_try_get(i);
+	if (IS_ERR(ld))
 		return 0;
-	seq_printf(m, "%-10s %2d\n", ld.ops->name ? ld.ops->name : "???", i);
-	tty_ldisc_put(ld.ops);
+	seq_printf(m, "%-10s %2d\n", ld->ops->name ? ld->ops->name : "???", i);
+	tty_ldisc_put(ld);
 	return 0;
 }
 
@@ -263,8 +271,7 @@ const struct file_operations tty_ldiscs_proc_fops = {
 
 static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
 {
-	ld->refcount = 0;
-	tty->ldisc = *ld;
+	tty->ldisc = ld;
 }
 
 /**
@@ -286,7 +293,7 @@ static int tty_ldisc_try(struct tty_struct *tty)
 	int ret = 0;
 
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	ld = &tty->ldisc;
+	ld = tty->ldisc;
 	if (test_bit(TTY_LDISC, &tty->flags)) {
 		ld->refcount++;
 		ret = 1;
@@ -315,10 +322,9 @@ struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
 {
 	/* wait_event is a macro */
 	wait_event(tty_ldisc_wait, tty_ldisc_try(tty));
-	WARN_ON(tty->ldisc.refcount == 0);
-	return &tty->ldisc;
+	WARN_ON(tty->ldisc->refcount == 0);
+	return tty->ldisc;
 }
-
 EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
 
 /**
@@ -335,10 +341,9 @@ EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
 {
 	if (tty_ldisc_try(tty))
-		return &tty->ldisc;
+		return tty->ldisc;
 	return NULL;
 }
-
 EXPORT_SYMBOL_GPL(tty_ldisc_ref);
 
 /**
@@ -366,7 +371,6 @@ void tty_ldisc_deref(struct tty_ldisc *ld)
 		wake_up(&tty_ldisc_wait);
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 }
-
 EXPORT_SYMBOL_GPL(tty_ldisc_deref);
 
 /**
@@ -389,6 +393,26 @@ void tty_ldisc_enable(struct tty_struct *tty)
 }
 
 /**
+ *	tty_ldisc_flush	-	flush line discipline queue
+ *	@tty: tty
+ *
+ *	Flush the line discipline queue (if any) for this tty. If there
+ *	is no line discipline active this is a no-op.
+ */
+
+void tty_ldisc_flush(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld = tty_ldisc_ref(tty);
+	if (ld) {
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_ldisc_deref(ld);
+	}
+	tty_buffer_flush(tty);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+
+/**
  *	tty_set_termios_ldisc		-	set ldisc field
  *	@tty: tty structure
  *	@num: line discipline number
@@ -407,6 +431,39 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
 	mutex_unlock(&tty->termios_mutex);
 }
 
+/**
+ *	tty_ldisc_open		-	open a line discipline
+ *	@tty: tty we are opening the ldisc on
+ *	@ld: discipline to open
+ *
+ *	A helper opening method. Also a convenient debugging and check
+ *	point.
+ */
+
+static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
+	if (ld->ops->open)
+		return ld->ops->open(tty);
+	return 0;
+}
+
+/**
+ *	tty_ldisc_close		-	close a line discipline
+ *	@tty: tty we are opening the ldisc on
+ *	@ld: discipline to close
+ *
+ *	A helper close method. Also a convenient debugging and check
+ *	point.
+ */
+
+static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));
+	clear_bit(TTY_LDISC_OPEN, &tty->flags);
+	if (ld->ops->close)
+		ld->ops->close(tty);
+}
 
 /**
  *	tty_ldisc_restore	-	helper for tty ldisc change
@@ -420,66 +477,136 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
 static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
 {
 	char buf[64];
-	struct tty_ldisc new_ldisc;
+	struct tty_ldisc *new_ldisc;
+	int r;
 
 	/* There is an outstanding reference here so this is safe */
-	tty_ldisc_get(old->ops->num, old);
+	old = tty_ldisc_get(old->ops->num);
+	WARN_ON(IS_ERR(old));
 	tty_ldisc_assign(tty, old);
 	tty_set_termios_ldisc(tty, old->ops->num);
-	if (old->ops->open && (old->ops->open(tty) < 0)) {
-		tty_ldisc_put(old->ops);
+	if (tty_ldisc_open(tty, old) < 0) {
+		tty_ldisc_put(old);
 		/* This driver is always present */
-		if (tty_ldisc_get(N_TTY, &new_ldisc) < 0)
+		new_ldisc = tty_ldisc_get(N_TTY);
+		if (IS_ERR(new_ldisc))
 			panic("n_tty: get");
-		tty_ldisc_assign(tty, &new_ldisc);
+		tty_ldisc_assign(tty, new_ldisc);
 		tty_set_termios_ldisc(tty, N_TTY);
-		if (new_ldisc.ops->open) {
-			int r = new_ldisc.ops->open(tty);
-				if (r < 0)
-				panic("Couldn't open N_TTY ldisc for "
-				      "%s --- error %d.",
-				      tty_name(tty, buf), r);
-		}
+		r = tty_ldisc_open(tty, new_ldisc);
+		if (r < 0)
+			panic("Couldn't open N_TTY ldisc for "
+			      "%s --- error %d.",
+			      tty_name(tty, buf), r);
 	}
 }
 
 /**
+ *	tty_ldisc_halt		-	shut down the line discipline
+ *	@tty: tty device
+ *
+ *	Shut down the line discipline and work queue for this tty device.
+ *	The TTY_LDISC flag being cleared ensures no further references can
+ *	be obtained while the delayed work queue halt ensures that no more
+ *	data is fed to the ldisc.
+ *
+ *	In order to wait for any existing references to complete see
+ *	tty_ldisc_wait_idle.
+ */
+
+static int tty_ldisc_halt(struct tty_struct *tty)
+{
+	clear_bit(TTY_LDISC, &tty->flags);
+	return cancel_delayed_work(&tty->buf.work);
+}
+
+/**
+ *	tty_ldisc_wait_idle	-	wait for the ldisc to become idle
+ *	@tty: tty to wait for
+ *
+ *	Wait for the line discipline to become idle. The discipline must
+ *	have been halted for this to guarantee it remains idle.
+ *
+ *	tty_ldisc_lock protects the ref counts currently.
+ */
+
+static int tty_ldisc_wait_idle(struct tty_struct *tty)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	while (tty->ldisc->refcount) {
+		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+		if (wait_event_timeout(tty_ldisc_wait,
+				tty->ldisc->refcount == 0, 5 * HZ) == 0)
+			return -EBUSY;
+		spin_lock_irqsave(&tty_ldisc_lock, flags);
+	}
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	return 0;
+}
+
+/**
  *	tty_set_ldisc		-	set line discipline
  *	@tty: the terminal to set
  *	@ldisc: the line discipline
  *
  *	Set the discipline of a tty line. Must be called from a process
- *	context.
+ *	context. The ldisc change logic has to protect itself against any
+ *	overlapping ldisc change (including on the other end of pty pairs),
+ *	the close of one side of a tty/pty pair, and eventually hangup.
  *
- *	Locking: takes tty_ldisc_lock.
- *		 called functions take termios_mutex
+ *	Locking: takes tty_ldisc_lock, termios_mutex
  */
 
 int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 {
 	int retval;
-	struct tty_ldisc o_ldisc, new_ldisc;
-	int work;
-	unsigned long flags;
+	struct tty_ldisc *o_ldisc, *new_ldisc;
+	int work, o_work = 0;
 	struct tty_struct *o_tty;
 
-restart:
-	/* This is a bit ugly for now but means we can break the 'ldisc
-	   is part of the tty struct' assumption later */
-	retval = tty_ldisc_get(ldisc, &new_ldisc);
-	if (retval)
-		return retval;
+	new_ldisc = tty_ldisc_get(ldisc);
+	if (IS_ERR(new_ldisc))
+		return PTR_ERR(new_ldisc);
+
+	/*
+	 *	We need to look at the tty locking here for pty/tty pairs
+	 *	when both sides try to change in parallel.
+	 */
+
+	o_tty = tty->link;	/* o_tty is the pty side or NULL */
+
+
+	/*
+	 *	Check the no-op case
+	 */
+
+	if (tty->ldisc->ops->num == ldisc) {
+		tty_ldisc_put(new_ldisc);
+		return 0;
+	}
 
 	/*
 	 *	Problem: What do we do if this blocks ?
+	 *	We could deadlock here
 	 */
 
 	tty_wait_until_sent(tty, 0);
 
-	if (tty->ldisc.ops->num == ldisc) {
-		tty_ldisc_put(new_ldisc.ops);
-		return 0;
+	mutex_lock(&tty->ldisc_mutex);
+
+	/*
+	 *	We could be midstream of another ldisc change which has
+	 *	dropped the lock during processing. If so we need to wait.
+	 */
+
+	while (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
+		mutex_unlock(&tty->ldisc_mutex);
+		wait_event(tty_ldisc_wait,
+			test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0);
+		mutex_lock(&tty->ldisc_mutex);
 	}
+	set_bit(TTY_LDISC_CHANGING, &tty->flags);
 
 	/*
 	 *	No more input please, we are switching. The new ldisc
@@ -489,8 +616,6 @@ restart:
 	tty->receive_room = 0;
 
 	o_ldisc = tty->ldisc;
-	o_tty = tty->link;
-
 	/*
 	 *	Make sure we don't change while someone holds a
 	 *	reference to the line discipline. The TTY_LDISC bit
@@ -501,108 +626,181 @@ restart:
 	 *	with a userspace app continually trying to use the tty in
 	 *	parallel to the change and re-referencing the tty.
 	 */
-	clear_bit(TTY_LDISC, &tty->flags);
-	if (o_tty)
-		clear_bit(TTY_LDISC, &o_tty->flags);
 
-	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
-		if (tty->ldisc.refcount) {
-			/* Free the new ldisc we grabbed. Must drop the lock
-			   first. */
-			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-			tty_ldisc_put(o_ldisc.ops);
-			/*
-			 * There are several reasons we may be busy, including
-			 * random momentary I/O traffic. We must therefore
-			 * retry. We could distinguish between blocking ops
-			 * and retries if we made tty_ldisc_wait() smarter.
-			 * That is up for discussion.
-			 */
-			if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
-				return -ERESTARTSYS;
-			goto restart;
-		}
-		if (o_tty && o_tty->ldisc.refcount) {
-			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-			tty_ldisc_put(o_tty->ldisc.ops);
-			if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0)
-				return -ERESTARTSYS;
-			goto restart;
-		}
-	}
-	/*
-	 *	If the TTY_LDISC bit is set, then we are racing against
-	 *	another ldisc change
-	 */
-	if (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
-		struct tty_ldisc *ld;
-		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-		tty_ldisc_put(new_ldisc.ops);
-		ld = tty_ldisc_ref_wait(tty);
-		tty_ldisc_deref(ld);
-		goto restart;
-	}
-	/*
-	 *	This flag is used to avoid two parallel ldisc changes. Once
-	 *	open and close are fine grained locked this may work better
-	 *	as a mutex shared with the open/close/hup paths
-	 */
-	set_bit(TTY_LDISC_CHANGING, &tty->flags);
+	work = tty_ldisc_halt(tty);
 	if (o_tty)
-		set_bit(TTY_LDISC_CHANGING, &o_tty->flags);
-	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-	
-	/*
-	 *	From this point on we know nobody has an ldisc
-	 *	usage reference, nor can they obtain one until
-	 *	we say so later on.
-	 */
+		o_work = tty_ldisc_halt(o_tty);
 
-	work = cancel_delayed_work(&tty->buf.work);
 	/*
-	 * Wait for ->hangup_work and ->buf.work handlers to terminate
-	 * MUST NOT hold locks here.
+	 * Wait for ->hangup_work and ->buf.work handlers to terminate.
+	 * We must drop the mutex here in case a hangup is also in process.
 	 */
+
+	mutex_unlock(&tty->ldisc_mutex);
+
 	flush_scheduled_work();
+
+	/* Let any existing reference holders finish */
+	retval = tty_ldisc_wait_idle(tty);
+	if (retval < 0) {
+		clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+		tty_ldisc_put(new_ldisc);
+		return retval;
+	}
+
+	mutex_lock(&tty->ldisc_mutex);
+	if (test_bit(TTY_HUPPED, &tty->flags)) {
+		/* We were raced by the hangup method. It will have stomped
+		   the ldisc data and closed the ldisc down */
+		clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+		mutex_unlock(&tty->ldisc_mutex);
+		tty_ldisc_put(new_ldisc);
+		return -EIO;
+	}
+
 	/* Shutdown the current discipline. */
-	if (o_ldisc.ops->close)
-		(o_ldisc.ops->close)(tty);
+	tty_ldisc_close(tty, o_ldisc);
 
 	/* Now set up the new line discipline. */
-	tty_ldisc_assign(tty, &new_ldisc);
+	tty_ldisc_assign(tty, new_ldisc);
 	tty_set_termios_ldisc(tty, ldisc);
-	if (new_ldisc.ops->open)
-		retval = (new_ldisc.ops->open)(tty);
+
+	retval = tty_ldisc_open(tty, new_ldisc);
 	if (retval < 0) {
-		tty_ldisc_put(new_ldisc.ops);
-		tty_ldisc_restore(tty, &o_ldisc);
+		/* Back to the old one or N_TTY if we can't */
+		tty_ldisc_put(new_ldisc);
+		tty_ldisc_restore(tty, o_ldisc);
 	}
+
 	/* At this point we hold a reference to the new ldisc and a
 	   a reference to the old ldisc. If we ended up flipping back
 	   to the existing ldisc we have two references to it */
 
-	if (tty->ldisc.ops->num != o_ldisc.ops->num && tty->ops->set_ldisc)
+	if (tty->ldisc->ops->num != o_ldisc->ops->num && tty->ops->set_ldisc)
 		tty->ops->set_ldisc(tty);
 
-	tty_ldisc_put(o_ldisc.ops);
+	tty_ldisc_put(o_ldisc);
 
 	/*
-	 *	Allow ldisc referencing to occur as soon as the driver
-	 *	ldisc callback completes.
+	 *	Allow ldisc referencing to occur again
 	 */
 
 	tty_ldisc_enable(tty);
 	if (o_tty)
 		tty_ldisc_enable(o_tty);
 
-	/* Restart it in case no characters kick it off. Safe if
+	/* Restart the work queue in case no characters kick it off. Safe if
 	   already running */
 	if (work)
 		schedule_delayed_work(&tty->buf.work, 1);
+	if (o_work)
+		schedule_delayed_work(&o_tty->buf.work, 1);
+	mutex_unlock(&tty->ldisc_mutex);
 	return retval;
 }
 
+/**
+ *	tty_reset_termios	-	reset terminal state
+ *	@tty: tty to reset
+ *
+ *	Restore a terminal to the driver default state.
+ */
+
+static void tty_reset_termios(struct tty_struct *tty)
+{
+	mutex_lock(&tty->termios_mutex);
+	*tty->termios = tty->driver->init_termios;
+	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+	mutex_unlock(&tty->termios_mutex);
+}
+
+
+/**
+ *	tty_ldisc_reinit	-	reinitialise the tty ldisc
+ *	@tty: tty to reinit
+ *
+ *	Switch the tty back to N_TTY line discipline and leave the
+ *	ldisc state closed
+ */
+
+static void tty_ldisc_reinit(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+
+	tty_ldisc_close(tty, tty->ldisc);
+	tty_ldisc_put(tty->ldisc);
+	tty->ldisc = NULL;
+	/*
+	 *	Switch the line discipline back
+	 */
+	ld = tty_ldisc_get(N_TTY);
+	BUG_ON(IS_ERR(ld));
+	tty_ldisc_assign(tty, ld);
+	tty_set_termios_ldisc(tty, N_TTY);
+}
+
+/**
+ *	tty_ldisc_hangup		-	hangup ldisc reset
+ *	@tty: tty being hung up
+ *
+ *	Some tty devices reset their termios when they receive a hangup
+ *	event. In that situation we must also switch back to N_TTY properly
+ *	before we reset the termios data.
+ *
+ *	Locking: We can take the ldisc mutex as the rest of the code is
+ *	careful to allow for this.
+ *
+ *	In the pty pair case this occurs in the close() path of the
+ *	tty itself so we must be careful about locking rules.
+ */
+
+void tty_ldisc_hangup(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+
+	/*
+	 * FIXME! What are the locking issues here? This may me overdoing
+	 * things... This question is especially important now that we've
+	 * removed the irqlock.
+	 */
+	ld = tty_ldisc_ref(tty);
+	if (ld != NULL) {
+		/* We may have no line discipline at this point */
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_driver_flush_buffer(tty);
+		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
+		    ld->ops->write_wakeup)
+			ld->ops->write_wakeup(tty);
+		if (ld->ops->hangup)
+			ld->ops->hangup(tty);
+		tty_ldisc_deref(ld);
+	}
+	/*
+	 * FIXME: Once we trust the LDISC code better we can wait here for
+	 * ldisc completion and fix the driver call race
+	 */
+	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+	wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+	/*
+	 * Shutdown the current line discipline, and reset it to
+	 * N_TTY.
+	 */
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+		/* Avoid racing set_ldisc */
+		mutex_lock(&tty->ldisc_mutex);
+		/* Switch back to N_TTY */
+		tty_ldisc_reinit(tty);
+		/* At this point we have a closed ldisc and we want to
+		   reopen it. We could defer this to the next open but
+		   it means auditing a lot of other paths so this is a FIXME */
+		WARN_ON(tty_ldisc_open(tty, tty->ldisc));
+		tty_ldisc_enable(tty);
+		mutex_unlock(&tty->ldisc_mutex);
+		tty_reset_termios(tty);
+	}
+}
 
 /**
  *	tty_ldisc_setup			-	open line discipline
@@ -610,24 +808,23 @@ restart:
  *	@o_tty: pair tty for pty/tty pairs
  *
  *	Called during the initial open of a tty/pty pair in order to set up the
- *	line discplines and bind them to the tty.
+ *	line disciplines and bind them to the tty. This has no locking issues
+ *	as the device isn't yet active.
  */
 
 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
 {
-	struct tty_ldisc *ld = &tty->ldisc;
+	struct tty_ldisc *ld = tty->ldisc;
 	int retval;
 
-	if (ld->ops->open) {
-		retval = (ld->ops->open)(tty);
-		if (retval)
-			return retval;
-	}
-	if (o_tty && o_tty->ldisc.ops->open) {
-		retval = (o_tty->ldisc.ops->open)(o_tty);
+	retval = tty_ldisc_open(tty, ld);
+	if (retval)
+		return retval;
+
+	if (o_tty) {
+		retval = tty_ldisc_open(o_tty, o_tty->ldisc);
 		if (retval) {
-			if (ld->ops->close)
-				(ld->ops->close)(tty);
+			tty_ldisc_close(tty, ld);
 			return retval;
 		}
 		tty_ldisc_enable(o_tty);
@@ -635,32 +832,25 @@ int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
 	tty_ldisc_enable(tty);
 	return 0;
 }
-
 /**
  *	tty_ldisc_release		-	release line discipline
  *	@tty: tty being shut down
  *	@o_tty: pair tty for pty/tty pairs
  *
- *	Called during the final close of a tty/pty pair in order to shut down the
- *	line discpline layer.
+ *	Called during the final close of a tty/pty pair in order to shut down
+ *	the line discpline layer. On exit the ldisc assigned is N_TTY and the
+ *	ldisc has not been opened.
  */
 
 void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
 {
-	unsigned long flags;
-	struct tty_ldisc ld;
 	/*
 	 * Prevent flush_to_ldisc() from rescheduling the work for later.  Then
 	 * kill any delayed work. As this is the final close it does not
 	 * race with the set_ldisc code path.
 	 */
-	clear_bit(TTY_LDISC, &tty->flags);
-	cancel_delayed_work(&tty->buf.work);
-
-	/*
-	 * Wait for ->hangup_work and ->buf.work handlers to terminate
-	 */
 
+	tty_ldisc_halt(tty);
 	flush_scheduled_work();
 
 	/*
@@ -668,38 +858,19 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
 	 * side waiters as the file is closing so user count on the file
 	 * side is zero.
 	 */
-	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	while (tty->ldisc.refcount) {
-		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-		wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);
-		spin_lock_irqsave(&tty_ldisc_lock, flags);
-	}
-	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+	tty_ldisc_wait_idle(tty);
+
 	/*
 	 * Shutdown the current line discipline, and reset it to N_TTY.
 	 *
 	 * FIXME: this MUST get fixed for the new reflocking
 	 */
-	if (tty->ldisc.ops->close)
-		(tty->ldisc.ops->close)(tty);
-	tty_ldisc_put(tty->ldisc.ops);
 
-	/*
-	 *	Switch the line discipline back
-	 */
-	WARN_ON(tty_ldisc_get(N_TTY, &ld));
-	tty_ldisc_assign(tty, &ld);
-	tty_set_termios_ldisc(tty, N_TTY);
-	if (o_tty) {
-		/* FIXME: could o_tty be in setldisc here ? */
-		clear_bit(TTY_LDISC, &o_tty->flags);
-		if (o_tty->ldisc.ops->close)
-			(o_tty->ldisc.ops->close)(o_tty);
-		tty_ldisc_put(o_tty->ldisc.ops);
-		WARN_ON(tty_ldisc_get(N_TTY, &ld));
-		tty_ldisc_assign(o_tty, &ld);
-		tty_set_termios_ldisc(o_tty, N_TTY);
-	}
+	tty_ldisc_reinit(tty);
+	/* This will need doing differently if we need to lock */
+	if (o_tty)
+		tty_ldisc_release(o_tty, NULL);
 }
 
 /**
@@ -712,10 +883,10 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
 
 void tty_ldisc_init(struct tty_struct *tty)
 {
-	struct tty_ldisc ld;
-	if (tty_ldisc_get(N_TTY, &ld) < 0)
+	struct tty_ldisc *ld = tty_ldisc_get(N_TTY);
+	if (IS_ERR(ld))
 		panic("n_tty: init_tty");
-	tty_ldisc_assign(tty, &ld);
+	tty_ldisc_assign(tty, ld);
 }
 
 void tty_ldisc_begin(void)
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 9b8004c72686..62dadfc95e34 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -137,7 +137,7 @@ int tty_port_carrier_raised(struct tty_port *port)
 EXPORT_SYMBOL(tty_port_carrier_raised);
 
 /**
- *	tty_port_raise_dtr_rts	-	Riase DTR/RTS
+ *	tty_port_raise_dtr_rts	-	Raise DTR/RTS
  *	@port: tty port
  *
  *	Wrapper for the DTR/RTS raise logic. For the moment this is used
@@ -147,12 +147,28 @@ EXPORT_SYMBOL(tty_port_carrier_raised);
 
 void tty_port_raise_dtr_rts(struct tty_port *port)
 {
-	if (port->ops->raise_dtr_rts)
-		port->ops->raise_dtr_rts(port);
+	if (port->ops->dtr_rts)
+		port->ops->dtr_rts(port, 1);
 }
 EXPORT_SYMBOL(tty_port_raise_dtr_rts);
 
 /**
+ *	tty_port_lower_dtr_rts	-	Lower DTR/RTS
+ *	@port: tty port
+ *
+ *	Wrapper for the DTR/RTS raise logic. For the moment this is used
+ *	to hide some internal details. This will eventually become entirely
+ *	internal to the tty port.
+ */
+
+void tty_port_lower_dtr_rts(struct tty_port *port)
+{
+	if (port->ops->dtr_rts)
+		port->ops->dtr_rts(port, 0);
+}
+EXPORT_SYMBOL(tty_port_lower_dtr_rts);
+
+/**
  *	tty_port_block_til_ready	-	Waiting logic for tty open
  *	@port: the tty port being opened
  *	@tty: the tty device being bound
@@ -167,7 +183,7 @@ EXPORT_SYMBOL(tty_port_raise_dtr_rts);
  *		- port flags and counts
  *
  *	The passed tty_port must implement the carrier_raised method if it can
- *	do carrier detect and the raise_dtr_rts method if it supports software
+ *	do carrier detect and the dtr_rts method if it supports software
  *	management of these lines. Note that the dtr/rts raise is done each
  *	iteration as a hangup may have previously dropped them while we wait.
  */
@@ -182,7 +198,8 @@ int tty_port_block_til_ready(struct tty_port *port,
 
 	/* block if port is in the process of being closed */
 	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
-		interruptible_sleep_on(&port->close_wait);
+		wait_event_interruptible(port->close_wait,
+				!(port->flags & ASYNC_CLOSING));
 		if (port->flags & ASYNC_HUP_NOTIFY)
 			return -EAGAIN;
 		else
@@ -205,7 +222,6 @@ int tty_port_block_til_ready(struct tty_port *port,
 	   before the next open may complete */
 
 	retval = 0;
-	add_wait_queue(&port->open_wait, &wait);
 
 	/* The port lock protects the port counts */
 	spin_lock_irqsave(&port->lock, flags);
@@ -219,7 +235,7 @@ int tty_port_block_til_ready(struct tty_port *port,
 		if (tty->termios->c_cflag & CBAUD)
 			tty_port_raise_dtr_rts(port);
 
-		set_current_state(TASK_INTERRUPTIBLE);
+		prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
 		/* Check for a hangup or uninitialised port. Return accordingly */
 		if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
 			if (port->flags & ASYNC_HUP_NOTIFY)
@@ -240,8 +256,7 @@ int tty_port_block_til_ready(struct tty_port *port,
 		}
 		schedule();
 	}
-	set_current_state(TASK_RUNNING);
-	remove_wait_queue(&port->open_wait, &wait);
+	finish_wait(&port->open_wait, &wait);
 
 	/* Update counts. A parallel hangup will have set count to zero and
 	   we must not mess that up further */
@@ -292,6 +307,17 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
 	if (port->flags & ASYNC_INITIALIZED &&
 			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
 		tty_wait_until_sent(tty, port->closing_wait);
+	if (port->drain_delay) {
+		unsigned int bps = tty_get_baud_rate(tty);
+		long timeout;
+
+		if (bps > 1200)
+			timeout = max_t(long, (HZ * 10 * port->drain_delay) / bps,
+								HZ / 10);
+		else
+			timeout = 2 * HZ;
+		schedule_timeout_interruptible(timeout);
+	}
 	return 1;
 }
 EXPORT_SYMBOL(tty_port_close_start);
@@ -302,6 +328,9 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
 
 	tty_ldisc_flush(tty);
 
+	if (tty->termios->c_cflag & HUPCL)
+		tty_port_lower_dtr_rts(port);
+
 	spin_lock_irqsave(&port->lock, flags);
 	tty->closing = 0;
author	Linus Torvalds <torvalds@linux-foundation.org>	2009-06-11 08:57:47 -0700
committer	Linus Torvalds <torvalds@linux-foundation.org>	2009-06-11 08:57:47 -0700
commit	49c355617f603b8e71ec117c1f940152a998528a (patch)
tree	6b5e373003371bbe8c587a9fdda7bc4f0e791b03 /drivers/char
parent	991ec02cdca33b03a132a0cacfe6f0aa0be9aa8d (diff)
parent	f0e8527726b9e56649b9eafde3bc0fbc4dd2dd47 (diff)