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Commit d93d16e9 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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usb: cdc-wdm: Fix order in disconnect and fix locking 



- as the callback can schedule work, URBs must be killed first
- if the driver causes an autoresume, the caller must handle locking

Signed-off-by: default avatarOliver Neukum <neukum@b1-systems.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 62e66854

drivers/usb/class/cdc-wdm.c

+17 −8
Original line number Diff line number Diff line
@@ -776,9 +776,9 @@ static void wdm_disconnect(struct usb_interface *intf) 
	/* to terminate pending flushes */

	clear_bit(WDM_IN_USE, &desc->flags);

	spin_unlock_irqrestore(&desc->iuspin, flags);

	cancel_work_sync(&desc->rxwork);

	mutex_lock(&desc->lock);

	kill_urbs(desc);

	cancel_work_sync(&desc->rxwork);

	mutex_unlock(&desc->lock);

	wake_up_all(&desc->wait);

	if (!desc->count)
@@ -786,6 +786,7 @@ static void wdm_disconnect(struct usb_interface *intf) 
	mutex_unlock(&wdm_mutex);

}



#ifdef CONFIG_PM

static int wdm_suspend(struct usb_interface *intf, pm_message_t message)

{

	struct wdm_device *desc = usb_get_intfdata(intf);
@@ -793,27 +794,30 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message) 


	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);



	/* if this is an autosuspend the caller does the locking */

	if (!(message.event & PM_EVENT_AUTO))

		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);

		/* callback submits work - order is essential */

		kill_urbs(desc);

#ifdef CONFIG_PM

		cancel_work_sync(&desc->rxwork);

	}

#endif

	if (!(message.event & PM_EVENT_AUTO))

		mutex_unlock(&desc->lock);



	return rv;

}

#endif



static int recover_from_urb_loss(struct wdm_device *desc)

{
@@ -827,6 +831,8 @@ static int recover_from_urb_loss(struct wdm_device *desc) 
	}

	return rv;

}



#ifdef CONFIG_PM

static int wdm_resume(struct usb_interface *intf)

{

	struct wdm_device *desc = usb_get_intfdata(intf);
@@ -839,6 +845,7 @@ static int wdm_resume(struct usb_interface *intf) 
	mutex_unlock(&desc->lock);

	return rv;

}

#endif



static int wdm_pre_reset(struct usb_interface *intf)

{
@@ -862,9 +869,11 @@ static struct usb_driver wdm_driver = { 
	.name =		"cdc_wdm",

	.probe =	wdm_probe,

	.disconnect =	wdm_disconnect,

#ifdef CONFIG_PM

	.suspend =	wdm_suspend,

	.resume =	wdm_resume,

	.reset_resume =	wdm_resume,

#endif

	.pre_reset =	wdm_pre_reset,

	.post_reset =	wdm_post_reset,

	.id_table =	wdm_ids,