From: Jani Nikula <jani.nikula@intel.com>
Date: Tue, 7 May 2013 15:54:05 +0000 (+0300)
Subject: drm/i915: clear the stolen fb before resuming
X-Git-Tag: v3.9.3~50
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f28cecc16e43ca84d44e5d5fe7bc050e711d2c80;p=thirdparty%2Fkernel%2Fstable.git

drm/i915: clear the stolen fb before resuming

commit 1ffc5289bfcf7f4c4e4213240bb4be68c48ce603 upstream.

Similar to
commit 88afe715dd5469bc24ca7a19ac62dd3c241cab48
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Dec 16 12:15:41 2012 +0000

    drm/i915: Clear the stolen fb before enabling

but on the resume path.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=57191
Reported-and-tested-by: Nikolay Amiantov <nikoamia@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 981bdce3634eb..898832b9ee9c6 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -261,10 +261,22 @@ void intel_fbdev_fini(struct drm_device *dev)
 void intel_fbdev_set_suspend(struct drm_device *dev, int state)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
-	if (!dev_priv->fbdev)
+	struct intel_fbdev *ifbdev = dev_priv->fbdev;
+	struct fb_info *info;
+
+	if (!ifbdev)
 		return;
 
-	fb_set_suspend(dev_priv->fbdev->helper.fbdev, state);
+	info = ifbdev->helper.fbdev;
+
+	/* On resume from hibernation: If the object is shmemfs backed, it has
+	 * been restored from swap. If the object is stolen however, it will be
+	 * full of whatever garbage was left in there.
+	 */
+	if (!state && ifbdev->ifb.obj->stolen)
+		memset_io(info->screen_base, 0, info->screen_size);
+
+	fb_set_suspend(info, state);
 }
 
 MODULE_LICENSE("GPL and additional rights");