usb: cdc-wdm:Fix loss of data due to autosuspend

The guarding flag must be set and tested under spinlock
and cleared before the URBs are resubmitted in resume.

Signed-off-by: Oliver Neukum <neukum@b1-systems.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index a6b5e9fd0714..07c12974fe14 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -794,14 +794,17 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 
         mutex_lock(&desc->lock);
+        spin_lock_irq(&desc->iuspin);
 #ifdef CONFIG_PM
         if ((message.event & PM_EVENT_AUTO) &&
                         (test_bit(WDM_IN_USE, &desc->flags)
                         || test_bit(WDM_RESPONDING, &desc->flags))) {
+                spin_unlock_irq(&desc->iuspin);
                 rv = -EBUSY;
         } else {
 #endif
                 set_bit(WDM_SUSPENDING, &desc->flags);
+                spin_unlock_irq(&desc->iuspin);
                 cancel_work_sync(&desc->rxwork);
                 kill_urbs(desc);
 #ifdef CONFIG_PM
@@ -831,8 +834,8 @@ static int wdm_resume(struct usb_interface *intf)
 
         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
         mutex_lock(&desc->lock);
-        rv = recover_from_urb_loss(desc);
         clear_bit(WDM_SUSPENDING, &desc->flags);
+        rv = recover_from_urb_loss(desc);
         mutex_unlock(&desc->lock);
         return rv;
 }