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 19:28:10 +0000 (11:28 -0800)
commit38fee62c7ded145795c8f7fc4dafe7b41cc1ffde
treee5c50cdf8737ee6f448c1e0c8fa88aad81bdf972
parent692a66b4064dd7a600ab61652ca5167875352aca
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