diff options
Diffstat (limited to 'drivers/usb/core/urb.c')
| -rw-r--r-- | drivers/usb/core/urb.c | 169 |
1 files changed, 161 insertions, 8 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 47111e8..f263800 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -10,6 +10,8 @@ #define to_urb(d) container_of(d, struct urb, kref) +static DEFINE_SPINLOCK(usb_reject_lock); + static void urb_destroy(struct kref *kref) { struct urb *urb = to_urb(kref); @@ -68,7 +70,7 @@ struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) iso_packets * sizeof(struct usb_iso_packet_descriptor), mem_flags); if (!urb) { - err("alloc_urb: kmalloc failed"); + printk(KERN_ERR "alloc_urb: kmalloc failed\n"); return NULL; } usb_init_urb(urb); @@ -127,6 +129,13 @@ void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) usb_get_urb(urb); list_add_tail(&urb->anchor_list, &anchor->urb_list); urb->anchor = anchor; + + if (unlikely(anchor->poisoned)) { + spin_lock(&usb_reject_lock); + urb->reject++; + spin_unlock(&usb_reject_lock); + } + spin_unlock_irqrestore(&anchor->lock, flags); } EXPORT_SYMBOL_GPL(usb_anchor_urb); @@ -398,7 +407,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) /* fail if submitter gave bogus flags */ if (urb->transfer_flags != orig_flags) { - err("BOGUS urb flags, %x --> %x", + dev_err(&dev->dev, "BOGUS urb flags, %x --> %x\n", orig_flags, urb->transfer_flags); return -EINVAL; } @@ -544,25 +553,70 @@ EXPORT_SYMBOL_GPL(usb_unlink_urb); */ void usb_kill_urb(struct urb *urb) { - static DEFINE_MUTEX(reject_mutex); - might_sleep(); if (!(urb && urb->dev && urb->ep)) return; - mutex_lock(&reject_mutex); + spin_lock_irq(&usb_reject_lock); ++urb->reject; - mutex_unlock(&reject_mutex); + spin_unlock_irq(&usb_reject_lock); usb_hcd_unlink_urb(urb, -ENOENT); wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); - mutex_lock(&reject_mutex); + spin_lock_irq(&usb_reject_lock); --urb->reject; - mutex_unlock(&reject_mutex); + spin_unlock_irq(&usb_reject_lock); } EXPORT_SYMBOL_GPL(usb_kill_urb); /** + * usb_poison_urb - reliably kill a transfer and prevent further use of an URB + * @urb: pointer to URB describing a previously submitted request, + * may be NULL + * + * This routine cancels an in-progress request. It is guaranteed that + * upon return all completion handlers will have finished and the URB + * will be totally idle and cannot be reused. These features make + * this an ideal way to stop I/O in a disconnect() callback. + * If the request has not already finished or been unlinked + * the completion handler will see urb->status == -ENOENT. + * + * After and while the routine runs, attempts to resubmit the URB will fail + * with error -EPERM. Thus even if the URB's completion handler always + * tries to resubmit, it will not succeed and the URB will become idle. + * + * 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(). + */ +void usb_poison_urb(struct urb *urb) +{ + might_sleep(); + if (!(urb && urb->dev && urb->ep)) + return; + spin_lock_irq(&usb_reject_lock); + ++urb->reject; + spin_unlock_irq(&usb_reject_lock); + + usb_hcd_unlink_urb(urb, -ENOENT); + wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); +} +EXPORT_SYMBOL_GPL(usb_poison_urb); + +void usb_unpoison_urb(struct urb *urb) +{ + unsigned long flags; + + if (!urb) + return; + + spin_lock_irqsave(&usb_reject_lock, flags); + --urb->reject; + spin_unlock_irqrestore(&usb_reject_lock, flags); +} +EXPORT_SYMBOL_GPL(usb_unpoison_urb); + +/** * usb_kill_anchored_urbs - cancel transfer requests en masse * @anchor: anchor the requests are bound to * @@ -589,6 +643,35 @@ void usb_kill_anchored_urbs(struct usb_anchor *anchor) } EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); + +/** + * usb_poison_anchored_urbs - cease all traffic from an anchor + * @anchor: anchor the requests are bound to + * + * this allows all outstanding URBs to be poisoned starting + * from the back of the queue. Newly added URBs will also be + * poisoned + */ +void usb_poison_anchored_urbs(struct usb_anchor *anchor) +{ + struct urb *victim; + + spin_lock_irq(&anchor->lock); + anchor->poisoned = 1; + while (!list_empty(&anchor->urb_list)) { + victim = list_entry(anchor->urb_list.prev, struct urb, + anchor_list); + /* we must make sure the URB isn't freed before we kill it*/ + usb_get_urb(victim); + spin_unlock_irq(&anchor->lock); + /* this will unanchor the URB */ + usb_poison_urb(victim); + usb_put_urb(victim); + spin_lock_irq(&anchor->lock); + } + 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 @@ -633,3 +716,73 @@ int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, msecs_to_jiffies(timeout)); } EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); + +/** + * usb_get_from_anchor - get an anchor's oldest urb + * @anchor: the anchor whose urb you want + * + * this will take the oldest urb from an anchor, + * unanchor and return it + */ +struct urb *usb_get_from_anchor(struct usb_anchor *anchor) +{ + struct urb *victim; + unsigned long flags; + + spin_lock_irqsave(&anchor->lock, flags); + if (!list_empty(&anchor->urb_list)) { + victim = list_entry(anchor->urb_list.next, struct urb, + anchor_list); + usb_get_urb(victim); + spin_unlock_irqrestore(&anchor->lock, flags); + usb_unanchor_urb(victim); + } else { + spin_unlock_irqrestore(&anchor->lock, flags); + victim = NULL; + } + + return victim; +} + +EXPORT_SYMBOL_GPL(usb_get_from_anchor); + +/** + * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs + * @anchor: the anchor whose urbs you want to unanchor + * + * use this to get rid of all an anchor's urbs + */ +void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) +{ + struct urb *victim; + unsigned long flags; + + spin_lock_irqsave(&anchor->lock, flags); + while (!list_empty(&anchor->urb_list)) { + victim = list_entry(anchor->urb_list.prev, struct urb, + anchor_list); + usb_get_urb(victim); + spin_unlock_irqrestore(&anchor->lock, flags); + /* this may free the URB */ + usb_unanchor_urb(victim); + usb_put_urb(victim); + spin_lock_irqsave(&anchor->lock, flags); + } + spin_unlock_irqrestore(&anchor->lock, flags); +} + +EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); + +/** + * usb_anchor_empty - is an anchor empty + * @anchor: the anchor you want to query + * + * returns 1 if the anchor has no urbs associated with it + */ +int usb_anchor_empty(struct usb_anchor *anchor) +{ + return list_empty(&anchor->urb_list); +} + +EXPORT_SYMBOL_GPL(usb_anchor_empty); + |