usb: hub: Clear Port Reset Change during init/resume
authorJulius Werner <jwerner@chromium.org>
Wed, 16 Oct 2013 00:45:00 +0000 (17:45 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Nov 2013 19:11:52 +0000 (11:11 -0800)
commit1316580f10273f89629cc197f59cc7ad96d9605e
tree180a536be303ecfaaaaa401704efdab53669b9ac
parentbd7e08189efba225bfa173372b05682ac141af88
usb: hub: Clear Port Reset Change during init/resume

commit e92aee330837e4911553761490a8fb843f2053a6 upstream.

This patch adds the Port Reset Change flag to the set of bits that are
preemptively cleared on init/resume of a hub. In theory this bit should
never be set unexpectedly... in practice it can still happen if BIOS,
SMM or ACPI code plays around with USB devices without cleaning up
correctly. This is especially dangerous for XHCI root hubs, which don't
generate any more Port Status Change Events until all change bits are
cleared, so this is a good precaution to have (similar to how it's
already done for the Warm Port Reset Change flag).

Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c