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Commit 1431d2a4 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: get rid of urb->lock 



Now that urb->status isn't used, urb->lock doesn't protect anything.
This patch (as980) removes it and replaces it with a private mutex in
the one remaining place it was still used: usb_kill_urb.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4a00027d

drivers/usb/core/urb.c

+6 −5
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ void usb_init_urb(struct urb *urb) 
	if (urb) {

		memset(urb, 0, sizeof(*urb));

		kref_init(&urb->kref);

		spin_lock_init(&urb->lock);

		INIT_LIST_HEAD(&urb->anchor_list);

	}

}
@@ -541,19 +540,21 @@ int usb_unlink_urb(struct urb *urb) 
 */

void usb_kill_urb(struct urb *urb)

{

	static DEFINE_MUTEX(reject_mutex);



	might_sleep();

	if (!(urb && urb->dev && urb->ep))

		return;

	spin_lock_irq(&urb->lock);

	mutex_lock(&reject_mutex);

	++urb->reject;

	spin_unlock_irq(&urb->lock);

	mutex_unlock(&reject_mutex);



	usb_hcd_unlink_urb(urb, -ENOENT);

	wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);



	spin_lock_irq(&urb->lock);

	mutex_lock(&reject_mutex);

	--urb->reject;

	spin_unlock_irq(&urb->lock);

	mutex_unlock(&reject_mutex);

}



/**

include/linux/usb.h

+0 −4
Original line number Diff line number Diff line
@@ -1241,7 +1241,6 @@ struct urb 
{

	/* private: usb core and host controller only fields in the urb */

	struct kref kref;		/* reference count of the URB */

	spinlock_t lock;		/* lock for the URB */

	void *hcpriv;			/* private data for host controller */

	atomic_t use_count;		/* concurrent submissions counter */

	u8 reject;			/* submissions will fail */
@@ -1299,7 +1298,6 @@ static inline void usb_fill_control_urb (struct urb *urb, 
					 usb_complete_t complete_fn,

					 void *context)

{

	spin_lock_init(&urb->lock);

	urb->dev = dev;

	urb->pipe = pipe;

	urb->setup_packet = setup_packet;
@@ -1330,7 +1328,6 @@ static inline void usb_fill_bulk_urb (struct urb *urb, 
				      usb_complete_t complete_fn,

				      void *context)

{

	spin_lock_init(&urb->lock);

	urb->dev = dev;

	urb->pipe = pipe;

	urb->transfer_buffer = transfer_buffer;
@@ -1366,7 +1363,6 @@ static inline void usb_fill_int_urb (struct urb *urb, 
				     void *context,

				     int interval)

{

	spin_lock_init(&urb->lock);

	urb->dev = dev;

	urb->pipe = pipe;

	urb->transfer_buffer = transfer_buffer;