From 526867c3ca0caa2e3e846cb993b0f961c33c2abb Mon Sep 17 00:00:00 2001 From: Florian Wolter Date: Wed, 14 Aug 2013 10:33:16 +0200 Subject: [PATCH] xhci: Fix race between ep halt and URB cancellation The halted state of a endpoint cannot be cleared over CLEAR_HALT from a user process, because the stopped_td variable was overwritten in the handle_stopped_endpoint() function. So the xhci_endpoint_reset() function will refuse the reset and communication with device can not run over this endpoint. https://bugzilla.kernel.org/show_bug.cgi?id=60699 Signed-off-by: Florian Wolter Signed-off-by: Sarah Sharp --- drivers/usb/host/xhci-ring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index dd02402..6bfbd80 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -869,8 +869,12 @@ remove_finished_td: /* Otherwise ring the doorbell(s) to restart queued transfers */ ring_doorbell_for_active_rings(xhci, slot_id, ep_index); } - ep->stopped_td = NULL; - ep->stopped_trb = NULL; + + /* Clear stopped_td and stopped_trb if endpoint is not halted */ + if (!(ep->ep_state & EP_HALTED)) { + ep->stopped_td = NULL; + ep->stopped_trb = NULL; + } /* * Drop the lock and complete the URBs in the cancelled TD list. -- 2.7.4