redonkable/alistair23-linux
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USB: get rid of urb->lock

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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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2007-08-24 15:42:39 -04:00 committed by Greg Kroah-Hartman
parent 4a00027dcb
commit 1431d2a44c
2 changed files with 6 additions and 9 deletions
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11
drivers/usb/core/urb.c
View file

@ -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);
}
/**

4
include/linux/usb.h
View file

@ -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;