tree b31a7e28bd209bfd8cc6706f6dc84037a14bd48f
parent e78832cdca2ddd23c15abaed642cad1a39b3e122
author Hans de Goede <hdegoede@redhat.com> 1325716158 +0100
committer Sarah Sharp <sarah.a.sharp@linux.intel.com> 1325721028 -0800

xhci: Properly handle COMP_2ND_BW_ERR

I encountered a result of COMP_2ND_BW_ERR while improving how the pwc
webcam driver handles not having the full usb1 bandwidth available to
itself.

I created the following test setup, a NEC xhci controller with a
single TT USB 2 hub plugged into it, with a usb keyboard and a pwc webcam
plugged into the usb2 hub. This caused the following to show up in dmesg
when trying to stream from the pwc camera at its highest alt setting:

xhci_hcd 0000:01:00.0: ERROR: unexpected command completion code 0x23.
usb 6-2.1: Not enough bandwidth for altsetting 9

And usb_set_interface returned -EINVAL, which caused my pwc code to not
do the right thing as it expected -ENOSPC.

This patch makes the xhci driver properly handle COMP_2ND_BW_ERR and makes
usb_set_interface return -ENOSPC as expected.

This should be backported to stable kernels as old as 2.6.32.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org