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Subject[110/139] USB: cdc-acm: Update to new autopm API
2.6.33-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Oliver Neukum <oliver@neukum.org>

commit 97d35f95552c9a0ee4777a7f04431a9fd1260478 upstream.

Update cdc-acm to the async methods eliminating the workqueue

[This fixes a reported lockup for the cdc-acm driver - gregkh]

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/usb/class/cdc-acm.c | 43 ++++++++++++++++++++++---------------------
drivers/usb/class/cdc-acm.h | 1 -
2 files changed, 22 insertions(+), 22 deletions(-)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -170,6 +170,7 @@ static void acm_write_done(struct acm *a
{
wb->use = 0;
acm->transmitting--;
+ usb_autopm_put_interface_async(acm->control);
}

/*
@@ -211,9 +212,12 @@ static int acm_write_start(struct acm *a
}

dbg("%s susp_count: %d", __func__, acm->susp_count);
+ usb_autopm_get_interface_async(acm->control);
if (acm->susp_count) {
- acm->delayed_wb = wb;
- schedule_work(&acm->waker);
+ if (!acm->delayed_wb)
+ acm->delayed_wb = wb;
+ else
+ usb_autopm_put_interface_async(acm->control);
spin_unlock_irqrestore(&acm->write_lock, flags);
return 0; /* A white lie */
}
@@ -534,23 +538,6 @@ static void acm_softint(struct work_stru
tty_kref_put(tty);
}

-static void acm_waker(struct work_struct *waker)
-{
- struct acm *acm = container_of(waker, struct acm, waker);
- int rv;
-
- rv = usb_autopm_get_interface(acm->control);
- if (rv < 0) {
- dev_err(&acm->dev->dev, "Autopm failure in %s\n", __func__);
- return;
- }
- if (acm->delayed_wb) {
- acm_start_wb(acm, acm->delayed_wb);
- acm->delayed_wb = NULL;
- }
- usb_autopm_put_interface(acm->control);
-}
-
/*
* TTY handlers
*/
@@ -1178,7 +1165,6 @@ made_compressed_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);
init_waitqueue_head(&acm->drain_wait);
spin_lock_init(&acm->throttle_lock);
spin_lock_init(&acm->write_lock);
@@ -1343,7 +1329,6 @@ static void stop_data_traffic(struct acm
tasklet_enable(&acm->urb_task);

cancel_work_sync(&acm->work);
- cancel_work_sync(&acm->waker);
}

static void acm_disconnect(struct usb_interface *intf)
@@ -1435,6 +1420,7 @@ static int acm_suspend(struct usb_interf
static int acm_resume(struct usb_interface *intf)
{
struct acm *acm = usb_get_intfdata(intf);
+ struct acm_wb *wb;
int rv = 0;
int cnt;

@@ -1449,6 +1435,21 @@ static int acm_resume(struct usb_interfa
mutex_lock(&acm->mutex);
if (acm->port.count) {
rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
+
+ spin_lock_irq(&acm->write_lock);
+ if (acm->delayed_wb) {
+ wb = acm->delayed_wb;
+ acm->delayed_wb = NULL;
+ spin_unlock_irq(&acm->write_lock);
+ acm_start_wb(acm, acm->delayed_wb);
+ } else {
+ spin_unlock_irq(&acm->write_lock);
+ }
+
+ /*
+ * delayed error checking because we must
+ * do the write path at all cost
+ */
if (rv < 0)
goto err_out;

--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -112,7 +112,6 @@ struct acm {
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;
wait_queue_head_t drain_wait; /* close processing */
struct tasklet_struct urb_task; /* rx processing */
spinlock_t throttle_lock; /* synchronize throtteling and read callback */



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