From: Michel Dänzer <michel.daenzer@amd.com>
Date: Wed, 12 Jun 2013 09:58:44 +0000 (+0200)
Subject: drm: Don't pass negative delta to ktime_sub_ns()
X-Git-Tag: v3.11-rc5~16^2~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e91abf80a0998f326107874c88d549f94839f13c;p=pandora-kernel.git

drm: Don't pass negative delta to ktime_sub_ns()

It takes an unsigned value. This happens not to blow up on 64-bit
architectures, but it does on 32-bit, causing
drm_calc_vbltimestamp_from_scanoutpos() to calculate totally bogus
timestamps for vblank events. Which in turn causes e.g. gnome-shell to
hang after a DPMS off cycle with current xf86-video-ati Git.

[airlied: regression introduced in drm: use monotonic time in drm_calc_vbltimestamp_from_scanoutpos]

Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59339
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59836
Tested-by: shui yangwei <yangweix.shui@intel.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

Reading git-diff-tree failed