[Intel-gfx] [PATCH] drm/i915: Hold CRTC lock whilst freezing the planes

[Chris Wilson]

Daniel keeps on ramping up the warning level of the DRM and our display
core to make it complain whenever the locking rules are not followed.
This caught

commit 24576d23976746cb52e7700c4cadbf4bc1bc3472
Author: Jesse Barnes <jbarnes at virtuousgeek.org>
Date:   Tue Mar 26 09:25:45 2013 -0700

    drm/i915: enable VT switchless resume v3

introducing an unlocked access to the CRTC whilst disabling it for
suspend.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78114
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_drv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 591762c26af4..8450569ff42c 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -532,8 +532,11 @@ static int i915_drm_freeze(struct drm_device *dev)
 		 * for _thaw.
 		 */
 		mutex_lock(&dev->mode_config.mutex);
-		for_each_crtc(dev, crtc)
+		for_each_crtc(dev, crtc) {
+			mutex_lock(&crtc->mutex);
 			dev_priv->display.crtc_disable(crtc);
+			mutex_unlock(&crtc->mutex);
+		}
 		mutex_unlock(&dev->mode_config.mutex);
 
 		intel_modeset_suspend_hw(dev);
-- 
2.0.0.rc2