EHCI: fix criterion for resuming the root hub
authorAlan Stern <stern@rowland.harvard.edu>
Tue, 17 Apr 2012 19:24:15 +0000 (15:24 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 27 Apr 2012 17:16:50 +0000 (10:16 -0700)
commit10d6eea9355dbceb0b935dc69ae6ea9d47251391
tree818ba2b480175107608a675d4b2441f0da9c01f8
parent8b33e7d5c366b9b61db2e59915b9e5bf9df5f916
EHCI: fix criterion for resuming the root hub

commit dc75ce9d929aabeb0843a6b1a4ab320e58ba1597 upstream.

This patch (as1542) changes the criterion ehci-hcd uses to tell when
it needs to resume the controller's root hub.  A resume is needed when
a port status change is detected, obviously, but only if the root hub
is currently suspended.

Right now the driver tests whether the root hub is running, and that
is not the correct test.  In particular, if the controller has died
then the root hub should not be restarted.  In addition, some buggy
hardware occasionally requires the root hub to be running and
sending out SOF packets even while it is nominally supposed to be
suspended.

In the end, the test needs to be changed.  Rather than checking whether
the root hub is currently running, the driver will now check whether
the root hub is currently suspended.  This will yield the correct
behavior in all cases.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Peter Chen <B29397@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ehci-hcd.c