tree 704822e2b97d3a017fbe3d1e3f23396804f8da7a
parent c94a07b64d1c0e8f6921eedc719030675cbbfd69
author Shawn Nematbakhsh <shawnn@chromium.org> 1376933773 -0700
committer Matthias Kaehlcke <mka@google.com> 1433366105 -0700

usb: xhci: Disable runtime PM suspend for quirky controllers

commit c8476fb855434c733099079063990e5bfa7ecad6 upstream.

If a USB controller with XHCI_RESET_ON_RESUME goes to runtime suspend,
a reset will be performed upon runtime resume. Any previously suspended
devices attached to the controller will be re-enumerated at this time.
This will cause problems, for example, if an open system call on the
device triggered the resume (the open call will fail).

Note that this change is only relevant when persist_enabled is not set
for USB devices.

This patch should be backported to kernels as old as 3.0, that
contain the commit c877b3b2ad5cb9d4fe523c5496185cc328ff3ae9 "xhci: Add
reset on resume quirk for asrock p67 host".

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>