diff options
Diffstat (limited to 'drivers/usb/core/urb.c')
| -rw-r--r-- | drivers/usb/core/urb.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index f2638009a46..1f68af9db3f 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -85,8 +85,8 @@ EXPORT_SYMBOL_GPL(usb_alloc_urb); * Must be called when a user of a urb is finished with it. When the last user * of the urb calls this function, the memory of the urb is freed. * - * Note: The transfer buffer associated with the urb is not freed, that must be - * done elsewhere. + * Note: The transfer buffer associated with the urb is not freed unless the + * URB_FREE_BUFFER transfer flag is set. */ void usb_free_urb(struct urb *urb) { @@ -474,6 +474,12 @@ EXPORT_SYMBOL_GPL(usb_submit_urb); * indicating that the request has been canceled (rather than any other * code). * + * Drivers should not call this routine or related routines, such as + * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect + * method has returned. The disconnect function should synchronize with + * a driver's I/O routines to insure that all URB-related activity has + * completed before it returns. + * * This request is always asynchronous. Success is indicated by * returning -EINPROGRESS, at which time the URB will probably not yet * have been given back to the device driver. When it is eventually @@ -550,6 +556,9 @@ EXPORT_SYMBOL_GPL(usb_unlink_urb); * This routine may not be used in an interrupt context (such as a bottom * half or a completion handler), or when holding a spinlock, or in other * situations where the caller can't schedule(). + * + * This routine should not be called by a driver after its disconnect + * method has returned. */ void usb_kill_urb(struct urb *urb) { @@ -588,6 +597,9 @@ EXPORT_SYMBOL_GPL(usb_kill_urb); * This routine may not be used in an interrupt context (such as a bottom * half or a completion handler), or when holding a spinlock, or in other * situations where the caller can't schedule(). + * + * This routine should not be called by a driver after its disconnect + * method has returned. */ void usb_poison_urb(struct urb *urb) { @@ -622,6 +634,9 @@ EXPORT_SYMBOL_GPL(usb_unpoison_urb); * * this allows all outstanding URBs to be killed starting * from the back of the queue + * + * This routine should not be called by a driver after its disconnect + * method has returned. */ void usb_kill_anchored_urbs(struct usb_anchor *anchor) { @@ -651,6 +666,9 @@ EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); * this allows all outstanding URBs to be poisoned starting * from the back of the queue. Newly added URBs will also be * poisoned + * + * This routine should not be called by a driver after its disconnect + * method has returned. */ void usb_poison_anchored_urbs(struct usb_anchor *anchor) { @@ -672,6 +690,7 @@ void usb_poison_anchored_urbs(struct usb_anchor *anchor) spin_unlock_irq(&anchor->lock); } EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); + /** * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse * @anchor: anchor the requests are bound to @@ -680,6 +699,9 @@ EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); * from the back of the queue. This function is asynchronous. * The unlinking is just tiggered. It may happen after this * function has returned. + * + * This routine should not be called by a driver after its disconnect + * method has returned. */ void usb_unlink_anchored_urbs(struct usb_anchor *anchor) { |