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authorOliver Neukum <oliver@neukum.org>2008-06-20 11:25:57 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2008-07-21 15:16:36 -0700
commit11ea859d64b69a747d6b060b9ed1520eab1161fe (patch)
tree3b2de5ad788d145101762876e12c78c5b6383f93 /drivers/usb
parent188d63602756bfd4aa1fb61d531dbd59bddac962 (diff)
USB: additional power savings for cdc-acm devices that support remote wakeup
this patch saves power for cdc-acm devices that support remote wakeup while the device is connected. - request needs_remote_wakeup when needed - delayed write while a device is autoresumed - the device is marked busy when appropriate Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/class/cdc-acm.c142
-rw-r--r--drivers/usb/class/cdc-acm.h5
2 files changed, 126 insertions, 21 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index c3201affa0b6..ba86fec872b4 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -159,12 +159,34 @@ static void acm_write_done(struct acm *acm, struct acm_wb *wb)
spin_lock_irqsave(&acm->write_lock, flags);
acm->write_ready = 1;
wb->use = 0;
+ acm->transmitting--;
spin_unlock_irqrestore(&acm->write_lock, flags);
}
/*
* Poke write.
+ *
+ * the caller is responsible for locking
*/
+
+static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
+{
+ int rc;
+
+ acm->transmitting++;
+
+ wb->urb->transfer_buffer = wb->buf;
+ wb->urb->transfer_dma = wb->dmah;
+ wb->urb->transfer_buffer_length = wb->len;
+ wb->urb->dev = acm->dev;
+
+ if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
+ dbg("usb_submit_urb(write bulk) failed: %d", rc);
+ acm_write_done(acm, wb);
+ }
+ return rc;
+}
+
static int acm_write_start(struct acm *acm, int wbn)
{
unsigned long flags;
@@ -182,26 +204,31 @@ static int acm_write_start(struct acm *acm, int wbn)
return 0; /* A white lie */
}
+ wb = &acm->wb[wbn];
+ if(acm_wb_is_avail(acm) <= 1)
+ acm->write_ready = 0;
+
+ dbg("%s susp_count: %d", __func__, acm->susp_count);
+ if (acm->susp_count) {
+ acm->old_ready = acm->write_ready;
+ acm->delayed_wb = wb;
+ acm->write_ready = 0;
+ schedule_work(&acm->waker);
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ return 0; /* A white lie */
+ }
+ usb_mark_last_busy(acm->dev);
+
if (!acm_wb_is_used(acm, wbn)) {
spin_unlock_irqrestore(&acm->write_lock, flags);
return 0;
}
- wb = &acm->wb[wbn];
- if(acm_wb_is_avail(acm) <= 1)
- acm->write_ready = 0;
+ rc = acm_start_wb(acm, wb);
spin_unlock_irqrestore(&acm->write_lock, flags);
- wb->urb->transfer_buffer = wb->buf;
- wb->urb->transfer_dma = wb->dmah;
- wb->urb->transfer_buffer_length = wb->len;
- wb->urb->dev = acm->dev;
-
- if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
- dbg("usb_submit_urb(write bulk) failed: %d", rc);
- acm_write_done(acm, wb);
- }
return rc;
+
}
/*
* attributes exported through sysfs
@@ -304,6 +331,7 @@ static void acm_ctrl_irq(struct urb *urb)
break;
}
exit:
+ usb_mark_last_busy(acm->dev);
retval = usb_submit_urb (urb, GFP_ATOMIC);
if (retval)
err ("%s - usb_submit_urb failed with result %d",
@@ -320,8 +348,11 @@ static void acm_read_bulk(struct urb *urb)
dbg("Entering acm_read_bulk with status %d", status);
- if (!ACM_READY(acm))
+ if (!ACM_READY(acm)) {
+ dev_dbg(&acm->data->dev, "Aborting, acm not ready");
return;
+ }
+ usb_mark_last_busy(acm->dev);
if (status)
dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);
@@ -331,6 +362,7 @@ static void acm_read_bulk(struct urb *urb)
if (likely(status == 0)) {
spin_lock(&acm->read_lock);
+ acm->processing++;
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add_tail(&buf->list, &acm->filled_read_bufs);
spin_unlock(&acm->read_lock);
@@ -343,7 +375,8 @@ static void acm_read_bulk(struct urb *urb)
/* nevertheless the tasklet must be kicked unconditionally
so the queue cannot dry up */
}
- tasklet_schedule(&acm->urb_task);
+ if (likely(!acm->susp_count))
+ tasklet_schedule(&acm->urb_task);
}
static void acm_rx_tasklet(unsigned long _acm)
@@ -354,16 +387,23 @@ static void acm_rx_tasklet(unsigned long _acm)
struct acm_ru *rcv;
unsigned long flags;
unsigned char throttled;
+
dbg("Entering acm_rx_tasklet");
if (!ACM_READY(acm))
+ {
+ dbg("acm_rx_tasklet: ACM not ready");
return;
+ }
spin_lock_irqsave(&acm->throttle_lock, flags);
throttled = acm->throttle;
spin_unlock_irqrestore(&acm->throttle_lock, flags);
if (throttled)
+ {
+ dbg("acm_rx_tasklet: throttled");
return;
+ }
next_buffer:
spin_lock_irqsave(&acm->read_lock, flags);
@@ -403,6 +443,7 @@ urbs:
while (!list_empty(&acm->spare_read_bufs)) {
spin_lock_irqsave(&acm->read_lock, flags);
if (list_empty(&acm->spare_read_urbs)) {
+ acm->processing = 0;
spin_unlock_irqrestore(&acm->read_lock, flags);
return;
}
@@ -425,18 +466,23 @@ urbs:
rcv->urb->transfer_dma = buf->dma;
rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
- dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
-
/* This shouldn't kill the driver as unsuccessful URBs are returned to the
free-urbs-pool and resubmited ASAP */
- if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
+ spin_lock_irqsave(&acm->read_lock, flags);
+ if (acm->susp_count || usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
list_add(&buf->list, &acm->spare_read_bufs);
- spin_lock_irqsave(&acm->read_lock, flags);
list_add(&rcv->list, &acm->spare_read_urbs);
+ acm->processing = 0;
spin_unlock_irqrestore(&acm->read_lock, flags);
return;
+ } else {
+ spin_unlock_irqrestore(&acm->read_lock, flags);
+ dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
}
}
+ spin_lock_irqsave(&acm->read_lock, flags);
+ acm->processing = 0;
+ spin_unlock_irqrestore(&acm->read_lock, flags);
}
/* data interface wrote those outgoing bytes */
@@ -463,6 +509,27 @@ static void acm_softint(struct work_struct *work)
tty_wakeup(acm->tty);
}
+static void acm_waker(struct work_struct *waker)
+{
+ struct acm *acm = container_of(waker, struct acm, waker);
+ long flags;
+ int rv;
+
+ rv = usb_autopm_get_interface(acm->control);
+ if (rv < 0) {
+ err("Autopm failure in %s", __func__);
+ return;
+ }
+ if (acm->delayed_wb) {
+ acm_start_wb(acm, acm->delayed_wb);
+ acm->delayed_wb = NULL;
+ }
+ spin_lock_irqsave(&acm->write_lock, flags);
+ acm->write_ready = acm->old_ready;
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ usb_autopm_put_interface(acm->control);
+}
+
/*
* TTY handlers
*/
@@ -492,6 +559,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
if (usb_autopm_get_interface(acm->control) < 0)
goto early_bail;
+ else
+ acm->control->needs_remote_wakeup = 1;
mutex_lock(&acm->mutex);
if (acm->used++) {
@@ -509,6 +578,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
(acm->ctrl_caps & USB_CDC_CAP_LINE))
goto full_bailout;
+ usb_autopm_put_interface(acm->control);
INIT_LIST_HEAD(&acm->spare_read_urbs);
INIT_LIST_HEAD(&acm->spare_read_bufs);
@@ -570,12 +640,14 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
mutex_lock(&open_mutex);
if (!--acm->used) {
if (acm->dev) {
+ usb_autopm_get_interface(acm->control);
acm_set_control(acm, acm->ctrlout = 0);
usb_kill_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_kill_urb(acm->wb[i].urb);
for (i = 0; i < nr; i++)
usb_kill_urb(acm->ru[i].urb);
+ acm->control->needs_remote_wakeup = 0;
usb_autopm_put_interface(acm->control);
} else
acm_tty_unregister(acm);
@@ -987,6 +1059,7 @@ skip_normal_probe:
acm->urb_task.func = acm_rx_tasklet;
acm->urb_task.data = (unsigned long) acm;
INIT_WORK(&acm->work, acm_softint);
+ INIT_WORK(&acm->waker, acm_waker);
spin_lock_init(&acm->throttle_lock);
spin_lock_init(&acm->write_lock);
spin_lock_init(&acm->read_lock);
@@ -1116,6 +1189,7 @@ alloc_fail:
static void stop_data_traffic(struct acm *acm)
{
int i;
+ dbg("Entering stop_data_traffic");
tasklet_disable(&acm->urb_task);
@@ -1128,6 +1202,7 @@ static void stop_data_traffic(struct acm *acm)
tasklet_enable(&acm->urb_task);
cancel_work_sync(&acm->work);
+ cancel_work_sync(&acm->waker);
}
static void acm_disconnect(struct usb_interface *intf)
@@ -1181,8 +1256,27 @@ static void acm_disconnect(struct usb_interface *intf)
static int acm_suspend(struct usb_interface *intf, pm_message_t message)
{
struct acm *acm = usb_get_intfdata(intf);
+ int cnt;
+
+ if (acm->dev->auto_pm) {
+ int b;
+
+ spin_lock_irq(&acm->read_lock);
+ spin_lock(&acm->write_lock);
+ b = acm->processing + acm->transmitting;
+ spin_unlock(&acm->write_lock);
+ spin_unlock_irq(&acm->read_lock);
+ if (b)
+ return -EBUSY;
+ }
+
+ spin_lock_irq(&acm->read_lock);
+ spin_lock(&acm->write_lock);
+ cnt = acm->susp_count++;
+ spin_unlock(&acm->write_lock);
+ spin_unlock_irq(&acm->read_lock);
- if (acm->susp_count++)
+ if (cnt)
return 0;
/*
we treat opened interfaces differently,
@@ -1201,15 +1295,21 @@ static int acm_resume(struct usb_interface *intf)
{
struct acm *acm = usb_get_intfdata(intf);
int rv = 0;
+ int cnt;
- if (--acm->susp_count)
+ spin_lock_irq(&acm->read_lock);
+ acm->susp_count -= 1;
+ cnt = acm->susp_count;
+ spin_unlock_irq(&acm->read_lock);
+
+ if (cnt)
return 0;
mutex_lock(&acm->mutex);
if (acm->used) {
rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
if (rv < 0)
- goto err_out;
+ goto err_out;
tasklet_schedule(&acm->urb_task);
}
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index 046e064b033a..85c3aaaab7c5 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -107,10 +107,14 @@ struct acm {
struct list_head filled_read_bufs;
int write_used; /* number of non-empty write buffers */
int write_ready; /* write urb is not running */
+ int old_ready;
+ int processing;
+ int transmitting;
spinlock_t write_lock;
struct mutex mutex;
struct usb_cdc_line_coding line; /* bits, stop, parity */
struct work_struct work; /* work queue entry for line discipline waking up */
+ struct work_struct waker;
struct tasklet_struct urb_task; /* rx processing */
spinlock_t throttle_lock; /* synchronize throtteling and read callback */
unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */
@@ -123,6 +127,7 @@ struct acm {
unsigned char clocal; /* termios CLOCAL */
unsigned int ctrl_caps; /* control capabilities from the class specific header */
unsigned int susp_count; /* number of suspended interfaces */
+ struct acm_wb *delayed_wb; /* write queued for a device about to be woken */
};
#define CDC_DATA_INTERFACE_TYPE 0x0a