tree 10e9b58f9b93cbbc0ab375778396632d465ce28e
parent f0d7f27351058284f62ab4848909373c2d1f5ce8
author David Brownell <david-b@pacbell.net> 1163748898 -0800
committer Greg Kroah-Hartman <gregkh@suse.de> 1165011817 -0800

USB: add ehci_hcd.ignore_oc parameter

Certain boards seem to like to issue false overcurrent notifications, for
example on ports that don't have anything connected to them.  This looks
like a hardware error, at the level of noise to those ports' overcurrent
input signals (or non-debounced VBUS comparators).  This surfaces to users
as truly massive amounts of syslog spam from khubd (which is appropriate
for real hardware problems, except for the volume from multiple ports).

Using this new "ignore_oc" flag helps such systems work more sanely, by
preventing such indications from getting to khubd (and spam syslog).  The
downside is of course that true overcurrent errors will be masked; they'll
appear as spontaneous disconnects, without the diagnostics that will let
users troubleshoot issues like short circuited cables.

Note that the bulk of these reports seem to be with VIA southbridges, but
I think some were with Intel ones.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>