When the pipe A force quirk is applied the code will attempt to grab
a crtc mutex during intel_modeset_setup_hw_state(). If we're already
holding all crtc mutexes this will obviously deadlock every time.
So instead of using drm_modeset_lock_all() just grab the
mode_config.mutex. This is enough to avoid the unlocked mutex warnings
from certain lower level functions.
The regression was introduced in:
commit 027476642811f8559cbe00ef6cc54db230e48a20
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Mon Dec 2 11:08:06 2013 +0200
drm/i915: Take modeset locks around intel_modeset_setup_hw_state()
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
[danvet: Add cc: stable since the offending commit has that, too.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
7ad228b11e