summaryrefslogtreecommitdiff
path: root/drivers/tty
AgeCommit message (Collapse)Author
2014-06-11tty/serial: Add support for Altera serial portLey Foon Tan
commit e06c93cacb82dd147266fd1bdb2d0a0bd45ff2c1 upstream. Add support for Altera 8250/16550 compatible serial port. Signed-off-by: Ley Foon Tan <lftan@altera.com> [xr: Backported to 3.4: adjust filenames, context] Signed-off-by: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-118250/16?50: Add support for Broadcom TruManage redirected serial portStephen Hurd
commit ebebd49a8eab5e9aa1b1f8f1614ccc3c2120f886 upstream. Add support for the UART device present in Broadcom TruManage capable NetXtreme chips (ie: 5761m 5762, and 5725). This implementation has a hidden transmit FIFO, so running in single-byte interrupt mode results in too many interrupts. The UART_CAP_HFIFO capability was added to track this. It continues to reload the THR as long as the THRE and TSRE bits are set in the LSR up to a specified limit (1024 is used here). Signed-off-by: Stephen Hurd <shurd@broadcom.com> Signed-off-by: Michael Chan <mchan@broadcom.com> [xr: Backported to 3.4: - Adjust filenames - Adjust context - PORT_BRCM_TRUMANAGE is 22 not 24] Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-11Fix 4 port and add support for 8 port 'Unknown' PCI serial port cardsScott Ashcroft
commit d13402a4a944e72612a9ec5c9190e35717c02a9d upstream. I've managed to find an 8 port version of the card 4 port card which was discussed here: http://marc.info/?l=linux-serial&m=120760744205314&w=2 Looking back at that thread there were two issues in the original patch. 1) The I/O ports for the UARTs are within BAR2 not BAR0. This can been seen in the original post. 2) A serial quirk isn't needed as these cards have no memory in BAR0 which makes pci_plx9050_init just return. This patch fixes the 4 port support to use BAR2, removes the bogus quirk and adds support for the 8 port card. $ lspci -vvv -n -s 00:08.0 00:08.0 0780: 10b5:9050 (rev 01) Subsystem: 10b5:1588 Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 17 Region 1: I/O ports at ff00 [size=128] Region 2: I/O ports at fe00 [size=64] Region 3: I/O ports at fd00 [size=8] Capabilities: <access denied> Kernel driver in use: serial $ dmesg | grep 0000:00:08.0: [ 0.083320] pci 0000:00:08.0: [10b5:9050] type 0 class 0x000780 [ 0.083355] pci 0000:00:08.0: reg 14: [io 0xff00-0xff7f] [ 0.083369] pci 0000:00:08.0: reg 18: [io 0xfe00-0xfe3f] [ 0.083382] pci 0000:00:08.0: reg 1c: [io 0xfd00-0xfd07] [ 0.083460] pci 0000:00:08.0: PME# supported from D0 D3hot [ 1.212867] 0000:00:08.0: ttyS4 at I/O 0xfe00 (irq = 17) is a 16550A [ 1.233073] 0000:00:08.0: ttyS5 at I/O 0xfe08 (irq = 17) is a 16550A [ 1.253270] 0000:00:08.0: ttyS6 at I/O 0xfe10 (irq = 17) is a 16550A [ 1.273468] 0000:00:08.0: ttyS7 at I/O 0xfe18 (irq = 17) is a 16550A [ 1.293666] 0000:00:08.0: ttyS8 at I/O 0xfe20 (irq = 17) is a 16550A [ 1.313863] 0000:00:08.0: ttyS9 at I/O 0xfe28 (irq = 17) is a 16550A [ 1.334061] 0000:00:08.0: ttyS10 at I/O 0xfe30 (irq = 17) is a 16550A [ 1.354258] 0000:00:08.0: ttyS11 at I/O 0xfe38 (irq = 17) is a 16550A Signed-off-by: Scott Ashcroft <scott.ashcroft@talk21.com> [xr: Backported to 3.4: adjust context] Signed-off-by: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-11tty: Correct tty buffer flush.Ilya Zykov
commit 64325a3be08d364a62ee8f84b2cf86934bc2544a upstream. The root of problem is carelessly zeroing pointer(in function __tty_buffer_flush()), when another thread can use it. It can be cause of "NULL pointer dereference". Main idea of the patch, this is never free last (struct tty_buffer) in the active buffer. Only flush the data for ldisc(buf->head->read = buf->head->commit). At that moment driver can collect(write) data in buffer without conflict. It is repeat behavior of flush_to_ldisc(), only without feeding data to ldisc. Signed-off-by: Ilya Zykov <ilya@ilyx.ru> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-11serial: pch_uart: fix tty-kref leak in rx-error pathJohan Hovold
commit fc0919c68cb2f75bb1af759315f9d7e2a9443c28 upstream. Fix tty-kref leak introduced by commit 384e301e ("pch_uart: fix a deadlock when pch_uart as console") which never put its tty reference. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-11serial: pch_uart: fix tty-kref leak in dma-rx pathJohan Hovold
commit 19b85cfb190eb9980eaf416bff96aef4159a430e upstream. Fix tty_kref leak when tty_buffer_request room fails in dma-rx path. Note that the tty ref isn't really needed anymore, but as the leak has always been there, fixing it before removing should makes it easier to backport the fix. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07n_gsm: replace kfree_skb w/ appropriate dev_* versionsRuss Gorby
commit 329e56780e514a7ab607bcb51a52ab0dc2669414 upstream. Drivers are supposed to use the dev_* versions of the kfree_skb interfaces. In a couple of cases we were called with IRQs disabled as well which kfree_skb() does not expect. Replaced kfree_skb calls w/ dev_kfree_skb and dev_kfree_skb_any Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07n_gsm: avoid accessing freed memory during CMD_FCOFF conditionRuss Gorby
commit b4338e1efc339986cf6c0a3652906e914a86e2d3 upstream. gsm_data_kick was recently modified to allow messages on the tx queue bound for DLCI0 to flow even during FCOFF conditions. Unfortunately we introduced a bug discovered by code inspection where subsequent list traversers can access freed memory if the DLCI0 messages were not all at the head of the list. Replaced singly linked tx list w/ a list_head and used provided interfaces for traversing and deleting members. Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07char: n_gsm: remove message filtering for contipated DLCIsamix.lebsir
commit 10c6c383e43565c9c6ec07ff8eb2825f8091bdf0 upstream. The design of uplink flow control in the mux driver is that for constipated channels data will backup into the per-channel fifos, and any messages that make it to the outbound message queue will still go out. Code was added to also stop messages that were in the outbound queue but this requires filtering through all the messages on the queue for stopped dlcis and changes some of the mux logic unneccessarily. The message fiiltering was removed to be in line w/ the original design as the message filtering does not provide any solution. Extra debug messages used during investigation were also removed. Signed-off-by: samix.lebsir <samix.lebsir@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07n_gsm : Flow control handling in Mux driverFrederic Berat
commit c01af4fec2c8f303d6b3354d44308d9e6bef8026 upstream. - Correcting handling of FCon/FCoff in order to respect 27.010 spec - Consider FCon/off will overide all dlci flow control except for dlci0 as we must be able to send control frames. - Dlci constipated handling according to FC, RTC and RTR values. - Modifying gsm_dlci_data_kick and gsm_dlci_data_sweep according to dlci constipated value Signed-off-by: Frederic Berat <fredericx.berat@intel.com> Signed-off-by: Russ Gorby <russ.gorby@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07tty: serial: imx: don't reinit clock in imx_setup_ufcr()Dirk Behme
commit 7be0670f7b9198382938a03ff3db7f47ef6b4780 upstream. Remove the clock configuration from imx_setup_ufcr(). This isn't needed here and will cause garbage output if done. To be be sure that we only touch the bits we want (TXTL and RXTL) we have to mask out all other bits of the UFCR register. Add one non-existing bit macro for this, too (bit 6, DCEDTE on i.MX6). Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> CC: Shawn Guo <shawn.guo@linaro.org> CC: Sascha Hauer <s.hauer@pengutronix.de> CC: Troy Kisky <troy.kisky@boundarydevices.com> CC: Xinyu Chen <xinyu.chen@freescale.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: deleted code in imx_setup_ufcr() refers to sport->clk not sport->clk_per] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-18n_tty: Fix n_tty_write crash when echoing in raw modePeter Hurley
commit 4291086b1f081b869c6d79e5b7441633dc3ace00 upstream. The tty atomic_write_lock does not provide an exclusion guarantee for the tty driver if the termios settings are LECHO & !OPOST. And since it is unexpected and not allowed to call TTY buffer helpers like tty_insert_flip_string concurrently, this may lead to crashes when concurrect writers call pty_write. In that case the following two writers: * the ECHOing from a workqueue and * pty_write from the process race and can overflow the corresponding TTY buffer like follows. If we look into tty_insert_flip_string_fixed_flag, there is: int space = __tty_buffer_request_room(port, goal, flags); struct tty_buffer *tb = port->buf.tail; ... memcpy(char_buf_ptr(tb, tb->used), chars, space); ... tb->used += space; so the race of the two can result in something like this: A B __tty_buffer_request_room __tty_buffer_request_room memcpy(buf(tb->used), ...) tb->used += space; memcpy(buf(tb->used), ...) ->BOOM B's memcpy is past the tty_buffer due to the previous A's tb->used increment. Since the N_TTY line discipline input processing can output concurrently with a tty write, obtain the N_TTY ldisc output_lock to serialize echo output with normal tty writes. This ensures the tty buffer helper tty_insert_flip_string is not called concurrently and everything is fine. Note that this is nicely reproducible by an ordinary user using forkpty and some setup around that (raw termios + ECHO). And it is present in kernels at least after commit d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to use the normal buffering logic) in 2.6.31-rc3. js: add more info to the commit log js: switch to bool js: lock unconditionally js: lock only the tty->ops->write call References: CVE-2014-0196 Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: output_lock is a member of struct tty_struct] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2014-05-13drivers/tty/hvc: don't free hvc_console_setup after initTomoki Sekiyama
commit 501fed45b7e8836ee9373f4d31e2d85e3db6103a upstream. When 'console=hvc0' is specified to the kernel parameter in x86 KVM guest, hvc console is setup within a kthread. However, that will cause SEGV and the boot will fail when the driver is builtin to the kernel, because currently hvc_console_setup() is annotated with '__init'. This patch removes '__init' to boot the guest successfully with 'console=hvc0'. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-06hvc: ensure hvc_init is only ever called once in hvc_console.cPaul Gortmaker
commit f76a1cbed18c86e2d192455f0daebb48458965f3 upstream. Commit 3e6c6f630a5282df8f3393a59f10eb9c56536d23 ("Delay creation of khcvd thread") moved the call of hvc_init from being a device_initcall into hvc_alloc, and used a non-null hvc_driver as indication of whether hvc_init had already been called. The problem with this is that hvc_driver is only assigned a value at the bottom of hvc_init, and so there is a window where multiple hvc_alloc calls can be in progress at the same time and hence try and call hvc_init multiple times. Previously the use of device_init guaranteed that hvc_init was only called once. This manifests itself as sporadic instances of two hvc_init calls racing each other, and with the loser of the race getting -EBUSY from tty_register_driver() and hence that virtual console fails: Couldn't register hvc console driver virtio-ports vport0p1: error -16 allocating hvc for port Here we add an atomic_t to guarantee we'll never run hvc_init twice. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 3e6c6f630a52 ("Delay creation of khcvd thread") Reported-by: Jim Somerville <Jim.Somerville@windriver.com> Tested-by: Jim Somerville <Jim.Somerville@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-22tty: n_gsm: Fix for modems with brk in modem status controlLars Poeschel
commit 3ac06b905655b3ef2fd2196bab36e4587e1e4e4f upstream. 3GPP TS 07.10 states in section 5.4.6.3.7: "The length byte contains the value 2 or 3 ... depending on the break signal." The break byte is optional and if it is sent, the length is 3. In fact the driver was not able to work with modems that send this break byte in their modem status control message. If the modem just sends the break byte if it is really set, then weird things might happen. The code for deconding the modem status to the internal linux presentation in gsm_process_modem has already a big comment about this 2 or 3 byte length thing and it is already able to decode the brk, but the code calling the gsm_process_modem function in gsm_control_modem does not encode it and hand it over the right way. This patch fixes this. Without this fix if the modem sends the brk byte in it's modem status control message the driver will hang when opening a muxed channel. Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06serial: add support for 200 v3 series Titan cardYegor Yefremov
commit 48c0247d7b7bf58abb85a39021099529df365c4d upstream. Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06tty/serial: at91: Handle shutdown more safelyMarek Roszko
commit 0cc7c6c7916b1b6f34350ff1473b80b9f7e459c0 upstream. Interrupts were being cleaned up late in the shutdown handler, it is possible that an interrupt can occur and schedule a tasklet that runs after the port is cleaned up. There is a null dereference due to this race condition with the following stacktrace: [<c02092b0>] (atmel_tasklet_func+0x514/0x814) from [<c001fd34>] (tasklet_action+0x70/0xa8) [<c001fd34>] (tasklet_action+0x70/0xa8) from [<c001f60c>] (__do_softirq+0x90/0x144) [<c001f60c>] (__do_softirq+0x90/0x144) from [<c001fa18>] (irq_exit+0x40/0x4c) [<c001fa18>] (irq_exit+0x40/0x4c) from [<c000e298>] (handle_IRQ+0x64/0x84) [<c000e298>] (handle_IRQ+0x64/0x84) from [<c000d6c0>] (__irq_svc+0x40/0x50) [<c000d6c0>] (__irq_svc+0x40/0x50) from [<c0208060>] (atmel_rx_dma_release+0x88/0xb8) [<c0208060>] (atmel_rx_dma_release+0x88/0xb8) from [<c0209740>] (atmel_shutdown+0x104/0x160) [<c0209740>] (atmel_shutdown+0x104/0x160) from [<c0205e8c>] (uart_port_shutdown+0x2c/0x38) Signed-off-by: Marek Roszko <mark.roszko@gmail.com> Acked-by: Leilei Zhao <leilei.zhao@atmel.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-08TTY: pmac_zilog, check existence of ports in pmz_console_init()Geert Uytterhoeven
commit dc1dc2f8a5dd863bf2e79f338fc3ae29e99c683a upstream. When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0" on the kernel command line, it crashes with: Unable to handle kernel NULL pointer dereference at virtual address (null) Oops: 00000000 PC: [<0013ad28>] __pmz_startup+0x32/0x2a0 ... Call Trace: [<002c5d3e>] pmz_console_setup+0x64/0xe4 The normal tty driver doesn't crash, because init_pmz() checks pmz_ports_count again after calling pmz_probe(). In the serial console initialization path, pmz_console_init() doesn't do this, causing the driver to crash later. Add a check for pmz_ports_count to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-07powerpc/hvsi: Increase handshake timeout from 200ms to 400ms.Eugene Surovegin
commit d220980b701d838560a70de691b53be007e99e78 upstream. This solves a problem observed in kexec'ed kernel where 200ms timeout is too short and bootconsole fails to initialize. Console did eventually become workable but much later into the boot process. Observed timeout was around 260ms, but I decided to make it a little bigger for more reliability. This has been tested on Power7 machine with Petitboot as a primary bootloader and PowerNV firmware. Signed-off-by: Eugene Surovegin <surovegin@google.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-11serial/mxs-auart: increase time to wait for transmitter to become idleUwe Kleine-König
commit 079a036f4283e2b0e5c26080b8c5112bc0cc1831 upstream. Without this patch the driver waits ~1 ms for the UART to become idle. At 115200n8 this time is (theoretically) enough to transfer 11.5 characters (= 115200 bits/s / (10 Bits/char) * 1ms). As the mxs-auart has a fifo size of 16 characters the clock is gated too early. The problem is worse for lower baud rates. This only happens to really shut down the transmitter in the middle of a transfer if /dev/ttyAPPx isn't opened in userspace (e.g. by a getty) but was at least once (because the bootloader doesn't disable the transmitter). So increase the timeout to 20 ms which should be enough for 9600n8, too. Moreover skip gating the clock if the timeout is elapsed. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-11serial/mxs-auart: fix race condition in interrupt handlerUwe Kleine-König
commit d970d7fe65adff5efe75b4a73c4ffc9be57089f7 upstream. The handler needs to ack the pending events before actually handling them. Otherwise a new event might come in after it it considered non-pending or handled and is acked then without being handled. So this event is only noticed when the next interrupt happens. Without this patch an i.MX28 based machine running an rt-patched kernel regularly hangs during boot. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-13Revert "serial: 8250_pci: add support for another kind of NetMos Technology ↵Greg Kroah-Hartman
PCI 9835 Multi-I/O Controller" commit 828c6a102b1f2b8583fadc0e779c46b31d448f0b upstream. This reverts commit 8d2f8cd424ca0b99001f3ff4f5db87c4e525f366. As reported by Stefan, this device already works with the parport_serial driver, so the 8250_pci driver should not also try to grab it as well. Reported-by: Stefan Seyfried <stefan.seyfried@googlemail.com> Cc: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-03pch_uart: fix a deadlock when pch_uart as consoleLiang Li
commit 384e301e3519599b000c1a2ecd938b533fc15d85 upstream. When we use pch_uart as system console like 'console=ttyPCH0,115200', then 'send break' to it. We'll encounter the deadlock on a cpu/core, with interrupts disabled on the core. When we happen to have all irqs affinity to cpu0 then the deadlock on cpu0 actually deadlock whole system. In pch_uart_interrupt, we have spin_lock_irqsave(&priv->lock, flags) then call pch_uart_err_ir when break is received. Then the call to dev_err would actually call to pch_console_write then we'll run into another spin_lock(&priv->lock), with interrupts disabled. So in the call sequence lead by pch_uart_interrupt, we should be carefully to call functions that will 'print message to console' only in case the uart port is not being used as serial console. Signed-off-by: Liang Li <liang.li@windriver.com> Cc: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-07TTY: Fix tty miss restart after we turn off flow-controlWang YanQing
commit dab73b4eb9ef924a2b90dab84e539076d82b256f upstream. I meet emacs hang in start if I do the operation below: 1: echo 3 > /proc/sys/vm/drop_caches 2: emacs BigFile 3: Press CTRL-S follow 2 immediately Then emacs hang on, CTRL-Q can't resume, the terminal hang on, you can do nothing with this terminal except close it. The reason is before emacs takeover control the tty, we use CTRL-S to XOFF it. Then when emacs takeover the control, it may don't use the flow-control, so emacs hang. This patch fix it. This patch will fix a kind of strange tty relation hang problem, I believe I meet it with vim in ssh, and also see below bug report: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=465823 Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07tty: fix up atime/mtime mess, take threeLinus Torvalds
commit b0b885657b6c8ef63a46bc9299b2a7715d19acde upstream. We first tried to avoid updating atime/mtime entirely (commit b0de59b5733d: "TTY: do not update atime/mtime on read/write"), and then limited it to only update it occasionally (commit 37b7f3c76595: "TTY: fix atime/mtime regression"), but it turns out that this was both insufficient and overkill. It was insufficient because we let people attach to the shared ptmx node to see activity without even reading atime/mtime, and it was overkill because the "only once a minute" means that you can't really tell an idle person from an active one with 'w'. So this tries to fix the problem properly. It marks the shared ptmx node as un-notifiable, and it lowers the "only once a minute" to a few seconds instead - still long enough that you can't time individual keystrokes, but short enough that you can tell whether somebody is active or not. Reported-by: Simon Kirby <sim@hostway.ca> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07serial_core.c: add put_device() after device_find_child()Federico Vaga
commit 5a65dcc04cda41f4122aacc37a5a348454645399 upstream. The serial core uses device_find_child() but does not drop the reference to the retrieved child after using it. This patch add the missing put_device(). What I have done to test this issue. I used a machine with an AMBA PL011 serial driver. I tested the patch on next-20120408 because the last branch [next-20120415] does not boot on this board. For test purpose, I added some pr_info() messages to print the refcount after device_find_child() (lines: 1937,2009), and after put_device() (lines: 1947, 2021). Boot the machine *without* put_device(). Then: echo reboot > /sys/power/disk echo disk > /sys/power/state [ 87.058575] uart_suspend_port:1937 refcount 4 [ 87.058582] uart_suspend_port:1947 refcount 4 [ 87.098083] uart_resume_port:2009refcount 5 [ 87.098088] uart_resume_port:2021 refcount 5 echo disk > /sys/power/state [ 103.055574] uart_suspend_port:1937 refcount 6 [ 103.055580] uart_suspend_port:1947 refcount 6 [ 103.095322] uart_resume_port:2009 refcount 7 [ 103.095327] uart_resume_port:2021 refcount 7 echo disk > /sys/power/state [ 252.459580] uart_suspend_port:1937 refcount 8 [ 252.459586] uart_suspend_port:1947 refcount 8 [ 252.499611] uart_resume_port:2009 refcount 9 [ 252.499616] uart_resume_port:2021 refcount 9 The refcount continuously increased. Boot the machine *with* this patch. Then: echo reboot > /sys/power/disk echo disk > /sys/power/state [ 159.333559] uart_suspend_port:1937 refcount 4 [ 159.333566] uart_suspend_port:1947 refcount 3 [ 159.372751] uart_resume_port:2009 refcount 4 [ 159.372755] uart_resume_port:2021 refcount 3 echo disk > /sys/power/state [ 185.713614] uart_suspend_port:1937 refcount 4 [ 185.713621] uart_suspend_port:1947 refcount 3 [ 185.752935] uart_resume_port:2009 refcount 4 [ 185.752940] uart_resume_port:2021 refcount 3 echo disk > /sys/power/state [ 207.458584] uart_suspend_port:1937 refcount 4 [ 207.458591] uart_suspend_port:1947 refcount 3 [ 207.498598] uart_resume_port:2009 refcount 4 [ 207.498605] uart_resume_port:2021 refcount 3 The refcount correctly handled. Signed-off-by: Federico Vaga <federico.vaga@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01TTY: fix atime/mtime regressionJiri Slaby
commit 37b7f3c76595e23257f61bd80b223de8658617ee upstream. In commit b0de59b5733d ("TTY: do not update atime/mtime on read/write") we removed timestamps from tty inodes to fix a security issue and waited if something breaks. Well, 'w', the utility to find out logged users and their inactivity time broke. It shows that users are inactive since the time they logged in. To revert to the old behaviour while still preventing attackers to guess the password length, we update the timestamps in one-minute intervals by this patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01TTY: do not update atime/mtime on read/writeJiri Slaby
commit b0de59b5733d18b0d1974a060860a8b5c1b36a2e upstream. On http://vladz.devzero.fr/013_ptmx-timing.php, we can see how to find out length of a password using timestamps of /dev/ptmx. It is documented in "Timing Analysis of Keystrokes and Timing Attacks on SSH". To avoid that problem, do not update time when reading from/writing to a TTY. I am afraid of regressions as this is a behavior we have since 0.97 and apps may expect the time to be current, e.g. for monitoring whether there was a change on the TTY. Now, there is no change. So this would better have a lot of testing before it goes upstream. References: CVE-2013-0160 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05vt: synchronize_rcu() under spinlock is not nice...Al Viro
commit e8cd81693bbbb15db57d3c9aa7dd90eda4842874 upstream. vcs_poll_data_free() calls unregister_vt_notifier(), which calls atomic_notifier_chain_unregister(), which calls synchronize_rcu(). Do it *after* we'd dropped ->f_lock. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05tty: atmel_serial_probe(): index of atmel_ports[] fixPawel Wieczorkiewicz
commit 503bded92da283b2f31d87e054c4c6d30c3c2340 upstream. Index of atmel_ports[ATMEL_MAX_UART] should be smaller than ATMEL_MAX_UART. Signed-off-by: Pawel Wieczorkiewicz <wpawel@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-28sunsu: Fix panic in case of nonexistent port at "console=ttySY" cmdline optionTkhai Kirill
[ Upstream commit cb29529ea0030e60ef1bbbf8399a43d397a51526 ] If a machine has X (X < 4) sunsu ports and cmdline option "console=ttySY" is passed, where X < Y <= 4, than the following panic happens: Unable to handle kernel NULL pointer dereference TPC: <sunsu_console_setup+0x78/0xe0> RPC: <sunsu_console_setup+0x74/0xe0> I7: <register_console+0x378/0x3e0> Call Trace: [0000000000453a38] register_console+0x378/0x3e0 [0000000000576fa0] uart_add_one_port+0x2e0/0x340 [000000000057af40] su_probe+0x160/0x2e0 [00000000005b8a4c] platform_drv_probe+0xc/0x20 [00000000005b6c2c] driver_probe_device+0x12c/0x220 [00000000005b6da8] __driver_attach+0x88/0xa0 [00000000005b4df4] bus_for_each_dev+0x54/0xa0 [00000000005b5a54] bus_add_driver+0x154/0x260 [00000000005b7190] driver_register+0x50/0x180 [00000000006d250c] sunsu_init+0x18c/0x1e0 [00000000006c2668] do_one_initcall+0xe8/0x160 [00000000006c282c] kernel_init_freeable+0x12c/0x1e0 [0000000000603764] kernel_init+0x4/0x100 [0000000000405f64] ret_from_syscall+0x1c/0x2c [0000000000000000] (null) 1)Fix the panic; 2)Increment registered port number every successful probe. Signed-off-by: Kirill Tkhai <tkhai@yandex.ru> CC: David Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20TTY: do not reset master's packet modeJiri Slaby
commit b81273a132177edd806476b953f6afeb17b786d5 upstream. Now that login from util-linux is forced to drop all references to a TTY which it wants to hangup (to reach reference count 1) we are seeing issues with telnet. When login closes its last reference to the slave PTY, it also resets packet mode on the *master* side. And we have a race here. What telnet does is fork+exec of `login'. Then there are two scenarios: * `login' closes the slave TTY and resets thus master's packet mode, but even now telnet properly sets the mode, or * `telnetd' sets packet mode on the master, `login' closes the slave TTY and resets master's packet mode. The former case is OK. However the latter happens in much more cases, by the order of magnitude to be precise. So when one tries to login to such a messed telnet setup, they see the following: inux login: ogin incorrect Note the missing first letters -- telnet thinks it is still in the packet mode, so when it receives "linux login" from `login', it considers "l" as the type of the packet and strips it. SuS does not mention how the implementation should behave. Both BSDs I checked (Free and Net) do not reset the flag upon the last close. By this I am resurrecting an old bug, see References. We are hitting it regularly now, i.e. with updated util-linux, ergo login. Here, I am changing a behavior introduced back in 2.1 times. It would better have a long time testing before goes upstream. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Bryan Mason <bmason@redhat.com> References: https://lkml.org/lkml/2009/11/11/223 References: https://bugzilla.redhat.com/show_bug.cgi?id=504703 References: https://bugzilla.novell.com/show_bug.cgi?id=797042 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20tty: serial: fix typo "ARCH_S5P6450"Paul Bolle
commit 827aa0d36d486f359808c8fb931cf7a71011a09d upstream. This could have been either ARCH_S5P64X0 or CPU_S5P6450. Looking at commit 2555e663b367b8d555e76023f4de3f6338c28d6c ("ARM: S5P64X0: Add UART serial support for S5P6450") - which added this typo - makes clear this should be CPU_S5P6450. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20serial: 8250_pci: add support for another kind of NetMos Technology PCI 9835 ↵Wang YanQing
Multi-I/O Controller commit 8d2f8cd424ca0b99001f3ff4f5db87c4e525f366 upstream. 01:08.0 Communication controller: NetMos Technology PCI 9835 Multi-I/O Controller (rev 01) Subsystem: Device [1000:0012] Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 20 Region 0: I/O ports at e050 [size=8] Region 1: I/O ports at e040 [size=8] Region 2: I/O ports at e030 [size=8] Region 3: I/O ports at e020 [size=8] Region 4: I/O ports at e010 [size=8] Region 5: I/O ports at e000 [size=16] Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28fb: Yet another band-aid for fixing lockdep messTakashi Iwai
commit e93a9a868792ad71cdd09d75e5a02d8067473c4e upstream. I've still got lockdep warnings even after Alan's patch, and it seems that yet more band aids are required to paper over similar paths for unbind_con_driver() and unregister_con_driver(). After this hack, lockdep warnings are finally gone. Signed-off-by: Takashi Iwai <tiwai@suse.de> Cc: Alan Cox <alan@linux.intel.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Jiri Kosina <jkosina@suse.cz> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28fb: rework locking to fix lock ordering on takeoverAlan Cox
commit 50e244cc793d511b86adea24972f3a7264cae114 upstream. Adjust the console layer to allow a take over call where the caller already holds the locks. Make the fb layer lock in order. This is partly a band aid, the fb layer is terminally confused about the locking rules it uses for its notifiers it seems. [akpm@linux-foundation.org: remove stray non-ascii char, tidy comment] [akpm@linux-foundation.org: export do_take_over_console()] [airlied: cleanup another non-ascii char] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Jiri Kosina <jkosina@suse.cz> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28vgacon/vt: clear buffer attributes when we load a 512 character font (v2)Dave Airlie
commit 2a2483072393b27f4336ab068a1f48ca19ff1c1e upstream. When we switch from 256->512 byte font rendering mode, it means the current contents of the screen is being reinterpreted. The bit that holds the high bit of the 9-bit font, may have been previously set, and thus the new font misrenders. The problem case we see is grub2 writes spaces with the bit set, so it ends up with data like 0x820, which gets reinterpreted into 0x120 char which the font translates into G with a circumflex. This flashes up on screen at boot and is quite ugly. A current side effect of this patch though is that any rendering on the screen changes color to a slightly darker color, but at least the screen no longer corrupts. v2: as suggested by hpa, always clear the attribute space, whether we are are going to or from 512 chars. Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28tty: set_termios/set_termiox should not return -EINTROleg Nesterov
commit 183d95cdd834381c594d3aa801c1f9f9c0c54fa9 upstream. See https://bugzilla.redhat.com/show_bug.cgi?id=904907 read command causes bash to abort with double free or corruption (out). A simple test-case from Roman: // Compile the reproducer and send sigchld ti that process. // EINTR occurs even if SA_RESTART flag is set. void handler(int sig) { } main() { struct sigaction act; act.sa_handler = handler; act.sa_flags = SA_RESTART; sigaction (SIGCHLD, &act, 0); struct termio ttp; ioctl(0, TCGETA, &ttp); while(1) { if (ioctl(0, TCSETAW, ttp) < 0) { if (errno == EINTR) { fprintf(stderr, "BUG!"); return(1); } } } } Change set_termios/set_termiox to return -ERESTARTSYS to fix this particular problem. I didn't dare to change other EINTR's in drivers/tty/, but they look equally wrong. Reported-by: Roman Rakus <rrakus@redhat.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28tty: Prevent deadlock in n_gsm driverDirkjan Bussink
commit 4d9b109060f690f5c835130ff54165ae157b3087 upstream. This change fixes a deadlock when the multiplexer is closed while there are still client side ports open. When the multiplexer is closed and there are active tty's it tries to close them with tty_vhangup. This has a problem though, because tty_vhangup needs the tty_lock. This patch changes it to unlock the tty_lock before attempting the hangup and relocks afterwards. The additional call to tty_port_tty_set is needed because otherwise the port stays active because of the reference counter. This change also exposed another problem that other code paths don't expect that the multiplexer could have been closed. This patch also adds checks for these cases in the gsmtty_ class of function that could be called. The documentation explicitly states that "first close all virtual ports before closing the physical port" but we've found this to not always reality in our field situations. The GPRS / UTMS modem sometimes crashes and needs a power cycle in that case which means cleanly shutting down everything is not always possible. This change makes it much more robust for our situation where at least the system is recoverable with this patch and doesn't hang in a deadlock situation inside the kernel. The patch is against the long term support kernel (3.4.27) and should apply cleanly to more recent branches. Tested with a Telit GE864-QUADV2 and Telit HE910 modem. Signed-off-by: Dirkjan Bussink <dirkjan.bussink@nedap.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-21tty: 8250_dw: Fix inverted arguments to serial_out in IRQ handlerMaxime Ripard
commit 68e56cb3a068f9c30971c6117fbbd1e32918e49e upstream. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-21serial:ifx6x60:Delete SPI timer when shut down portchao bi
commit 014b9b4ce84281ccb3d723c792bed19815f3571a upstream. When shut down SPI port, it's possible that MRDY has been asserted and a SPI timer was activated waiting for SRDY assert, in the case, it needs to delete this timer. Signed-off-by: Chen Jun <jun.d.chen@intel.com> Signed-off-by: channing <chao.bi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-26Revert "serial: omap: fix software flow control"Felipe Balbi
commit a4f743851f74fc3e0cc40c13082e65c24139f481 upstream. This reverts commit 957ee7270d632245b43f6feb0e70d9a5e9ea6cf6 (serial: omap: fix software flow control). As Russell has pointed out, that commit isn't fixing Software Flow Control at all, and it actually makes it even more broken. It was agreed to revert this commit and use Russell's latest UART patches instead. Signed-off-by: Felipe Balbi <balbi@ti.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Tony Lindgren <tony@atomide.com> Cc: Andreas Bießmann <andreas.devel@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21kdb,vt_console: Fix missed data due to pager overrunsJason Wessel
commit 17b572e82032bc246324ce136696656b66d4e3f1 upstream. It is possible to miss data when using the kdb pager. The kdb pager does not pay attention to the maximum column constraint of the screen or serial terminal. This result is not incrementing the shown lines correctly and the pager will print more lines that fit on the screen. Obviously that is less than useful when using a VGA console where you cannot scroll back. The pager will now look at the kdb_buffer string to see how many characters are printed. It might not be perfect considering you can output ASCII that might move the cursor position, but it is a substantially better approximation for viewing dmesg and trace logs. This also means that the vt screen needs to set the kdb COLUMNS variable. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07n_gsm: memory leak in uplink error pathRuss Gorby
commit 88ed2a60610974443335c924d7cb8e5dcf9dbdc1 upstream. Uplink (TX) network data will go through gsm_dlci_data_output_framed there is a bug where if memory allocation fails, the skb which has already been pulled off the list will be lost. In addition TX skbs were being processed in LIFO order Fixed the memory leak, and changed to FIFO order processing Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Kappel, LaurentX <laurentx.kappel@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07n_gsm: added interlocking for gsm_data_lock for certain code pathsRuss Gorby
commit 5e44708f75b0f8712da715d6babb0c21089b2317 upstream. There were some locking holes in the management of the MUX's message queue for 2 code paths: 1) gsmld_write_wakeup 2) receipt of CMD_FCON flow-control message In both cases gsm_data_kick is called w/o locking so it can collide with other other instances of gsm_data_kick (pulling messages tx_tail) or potentially other instances of __gsm_data_queu (adding messages to tx_head) Changed to take the tx_lock in these 2 cases Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07n_gsm: uplink SKBs accumulate on listRuss Gorby
commit 192b6041e75bb4a2aae73834037038cea139a92d upstream. gsm_dlci_data_kick will not call any output function if tx_bytes > THRESH_LO furthermore it will call the output function only once if tx_bytes == 0 If the size of the IP writes are on the order of THRESH_LO we can get into a situation where skbs accumulate on the outbound list being starved for events to call the output function. gsm_dlci_data_kick now calls the sweep function when tx_bytes==0 Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Kappel, LaurentX <laurentx.kappel@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07n_gsm.c: Implement 3GPP27.010 DLC start-up procedure in MUXxiaojin
commit 7e8ac7b23b67416700dfb8b4136a4e81ce675b48 upstream. In 3GPP27.010 5.8.1, it defined: The TE multiplexer initiates the establishment of the multiplexer control channel by sending a SABM frame on DLCI 0 using the procedures of clause 5.4.1. Once the multiplexer channel is established other DLCs may be established using the procedures of clause 5.4.1. This patch implement 5.8.1 in MUX level, it make sure DLC0 is the first channel to be setup. [or for those not familiar with the specification: it was possible to try and open a data connection while the control channel was not yet fully open, which is a spec violation and confuses some modems] Signed-off-by: xiaojin <jin.xiao@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> [tweaked the order we check things and error code] Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07serial: set correct baud_base for EXSYS EX-41092 Dual 16950Flavio Leitner
commit 26e8220adb0aec43b7acafa0f1431760eee28522 upstream. Apparently the same card model has two IDs, so this patch complements the commit 39aced68d664291db3324d0fcf0985ab5626aac2 adding the missing one. Signed-off-by: Flavio Leitner <fbl@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07serial: pl011: handle corruption at high clock speedsLinus Walleij
commit c5dd553b9fd069892c9e2de734f4f604e280fa7a upstream. This works around a few glitches in the ST version of the PL011 serial driver when using very high baud rates, as we do in the Ux500: 3, 3.25, 4 and 4.05 Mbps. Problem Observed/rootcause: When using high baud-rates, and the baudrate*8 is getting close to the provided clock frequency (so a division factor close to 1), when using bursts of characters (so they are abutted), then it seems as if there is not enough time to detect the beginning of the start-bit which is a timing reference for the entire character, and thus the sampling moment of character bits is moving towards the end of each bit, instead of the middle. Fix: Increase slightly the RX baud rate of the UART above the theoretical baudrate by 5%. This will definitely give more margin time to the UART_RX to correctly sample the data at the middle of the bit period. Also fix the ages old copy-paste error in the very stressed comment, it's referencing the registers used in the PL010 driver rather than the PL011 ones. Signed-off-by: Guillaume Jaunet <guillaume.jaunet@stericsson.com> Signed-off-by: Christophe Arnal <christophe.arnal@stericsson.com> Signed-off-by: Matthias Locher <matthias.locher@stericsson.com> Signed-off-by: Rajanikanth HV <rajanikanth.hv@stericsson.com> Cc: Bibek Basu <bibek.basu@stericsson.com> Cc: Par-Gunnar Hjalmdahl <par-gunnar.hjalmdahl@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07serial: omap: fix software flow controlVikram Pandita
commit 957ee7270d632245b43f6feb0e70d9a5e9ea6cf6 upstream. Software flow control register bits were not defined correctly. Also clarify the IXON and IXOFF logic to reflect what userspace wants. Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Vikram Pandita <vikram.pandita@ti.com> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.0.4) at 2026-05-18 18:02:49 +0000