tree ef2c80195877d04cd4438fadea2201c3b6d4b2ec
parent a5964396190d0c40dd549c23848c282fffa5d1f2
author Lu Baolu <baolu.lu@linux.intel.com> 1447836501 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1447867481 -0800

usb: xhci: fix checking ep busy for CFC

Function ep_ring_is_processing() checks the dequeue pointer
in endpoint context to know whether an endpoint is busy with
processing TRBs. This is not correct since dequeue pointer
field in an endpoint context is only valid when the endpoint
is in Halted or Stopped states. This buggy code causes audio
noise when playing sound with USB headset connected to host
controllers which support CFC (one of xhci 1.1 features).

This patch should exist in stable kernel since v4.3.

Reported-and-tested-by: YD Tseng <yd_tseng@asmedia.com.tw>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Cc: stable <stable@vger.kernel.org> # v4.3
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>