| From | Ben Hutchings <> | Date | Mon, 21 Oct 2013 09:46:28 +0100 | Subject | [PATCH 3.2 143/149] xhci: Fix race between ep halt and URB cancellation |
| |
3.2.52-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Florian Wolter <wolly84@web.de>
commit 526867c3ca0caa2e3e846cb993b0f961c33c2abb upstream.
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 <wolly84@web.de> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/usb/host/xhci-ring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -879,8 +879,12 @@ 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.
|