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authorAndiry Xu <andiry.xu@amd.com>2010-08-09 13:56:15 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-23 20:50:16 -0700
commit14184f9b8047026f1812f49df074e89dad3a09bc (patch)
tree5492adad4d8ce5d263abbdad713c13a35b08202c /drivers/usb
parenta1669b2c64a9c8b031e0ac5cbf2692337a577f7c (diff)
USB: xHCI: update ring dequeue pointer when process missed tds
This patch fixes a isoc transfer bug reported by Sander Eikelenboom. When ep->skip is set, endpoint ring dequeue pointer should be updated when processed every missed td. Although ring dequeue pointer will also be updated when ep->skip is clear, leave it intact during missed tds processing may cause two issues: 1). If the very next valid transfer following missed tds is a short transfer, its actual_length will be miscalculated; 2). If there are too many missed tds during transfer, new inserted tds may found the transfer ring full and urb enqueue fails. Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Andiry Xu <andiry.xu@amd.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/xhci-ring.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 2f19f3a817c2..48e60d166ff0 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1551,6 +1551,10 @@ static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
/* calc actual length */
if (ep->skip) {
td->urb->iso_frame_desc[idx].actual_length = 0;
+ /* Update ring dequeue pointer */
+ while (ep_ring->dequeue != td->last_trb)
+ inc_deq(xhci, ep_ring, false);
+ inc_deq(xhci, ep_ring, false);
return finish_td(xhci, td, event_trb, event, ep, status, true);
}