diff options
Diffstat (limited to 'drivers/usb/core/hcd.c')
| -rw-r--r-- | drivers/usb/core/hcd.c | 49 |
1 files changed, 37 insertions, 12 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index b82a7d787add..59d5d506d73c 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -750,6 +750,7 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd) { struct urb *urb; int length; + int status; unsigned long flags; char buffer[6]; /* Any root hubs with > 31 ports? */ @@ -767,11 +768,17 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd) if (urb) { clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags); hcd->status_urb = NULL; + if (urb->transfer_buffer_length >= length) { + status = 0; + } else { + status = -EOVERFLOW; + length = urb->transfer_buffer_length; + } urb->actual_length = length; memcpy(urb->transfer_buffer, buffer, length); usb_hcd_unlink_urb_from_ep(hcd, urb); - usb_hcd_giveback_urb(hcd, urb, 0); + usb_hcd_giveback_urb(hcd, urb, status); } else { length = 0; set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags); @@ -1663,6 +1670,13 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags) urb->hcpriv = NULL; INIT_LIST_HEAD(&urb->urb_list); atomic_dec(&urb->use_count); + /* + * Order the write of urb->use_count above before the read + * of urb->reject below. Pairs with the memory barriers in + * usb_kill_urb() and usb_poison_urb(). + */ + smp_mb__after_atomic(); + atomic_dec(&urb->dev->urbnum); if (atomic_read(&urb->reject)) wake_up(&usb_kill_urb_queue); @@ -1772,6 +1786,13 @@ static void __usb_hcd_giveback_urb(struct urb *urb) usb_anchor_resume_wakeups(anchor); atomic_dec(&urb->use_count); + /* + * Order the write of urb->use_count above before the read + * of urb->reject below. Pairs with the memory barriers in + * usb_kill_urb() and usb_poison_urb(). + */ + smp_mb__after_atomic(); + if (unlikely(atomic_read(&urb->reject))) wake_up(&usb_kill_urb_queue); usb_put_urb(urb); @@ -1784,7 +1805,6 @@ static void usb_giveback_urb_bh(unsigned long param) spin_lock_irq(&bh->lock); bh->running = true; - restart: list_replace_init(&bh->head, &local_list); spin_unlock_irq(&bh->lock); @@ -1798,10 +1818,17 @@ static void usb_giveback_urb_bh(unsigned long param) bh->completing_ep = NULL; } - /* check if there are new URBs to giveback */ + /* + * giveback new URBs next time to prevent this function + * from not exiting for a long time. + */ spin_lock_irq(&bh->lock); - if (!list_empty(&bh->head)) - goto restart; + if (!list_empty(&bh->head)) { + if (bh->high_prio) + tasklet_hi_schedule(&bh->bh); + else + tasklet_schedule(&bh->bh); + } bh->running = false; spin_unlock_irq(&bh->lock); } @@ -1826,7 +1853,7 @@ static void usb_giveback_urb_bh(unsigned long param) void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status) { struct giveback_urb_bh *bh; - bool running, high_prio_bh; + bool running; /* pass status to tasklet via unlinked */ if (likely(!urb->unlinked)) @@ -1837,13 +1864,10 @@ void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status) return; } - if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) { + if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) bh = &hcd->high_prio_bh; - high_prio_bh = true; - } else { + else bh = &hcd->low_prio_bh; - high_prio_bh = false; - } spin_lock(&bh->lock); list_add_tail(&urb->urb_list, &bh->head); @@ -1852,7 +1876,7 @@ void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status) if (running) ; - else if (high_prio_bh) + else if (bh->high_prio) tasklet_hi_schedule(&bh->bh); else tasklet_schedule(&bh->bh); @@ -2860,6 +2884,7 @@ int usb_add_hcd(struct usb_hcd *hcd, /* initialize tasklets */ init_giveback_urb_bh(&hcd->high_prio_bh); + hcd->high_prio_bh.high_prio = true; init_giveback_urb_bh(&hcd->low_prio_bh); /* enable irqs just before we start the controller, |