commit f7f6f008f701ab3e4a4f785032d8024d676e11cb
author Julius Werner <jwerner@chromium.org> Tue Sep 03 16:44:15 2013 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> Mon Sep 16 19:38:40 2013 +0000
tree 4658d61519457e29e2af41c4ccffdf62c641abff
parent 68c24ca057a2e08813d7693159fd90460197659b

libpayload: usbhub: Don't clear PSC unless it was set

The current USB hub code always clears the port status change after
checking it, regardless of whether it was set in the first place. Since
this check runs on every poll, it might create a race condition where
the port status changes right between the GET_PORT_STATUS and the
CLEAR_FEATURE(C_PORT_CONNECT), thus clearing the statrus change flag
before it was ever read. Let's add one extra if() to avoid that possible
headache.

BUG=chrome-os-partner:21969
TEST=None

Change-Id: Idd46c2199dc6c240bd9ef068fbe70cccc88bac42
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/168098