[ 72/75] drm/i915: Hold mode_config lock whilst changing mode for lastclose()

[Greg KH]

3.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

commit c291be9dba370ba696a0d482249a212cf5c15f45 upstream.

Upon lastclose(), we switch back to the fbcon configuration. This
requires taking the mode_config lock in order to serialise the change
with output probing elsewhere.

Reported-by: Oleksij Rempel <bug-track@xxxxxxxxxxxxxxxxx>
References: https://bugs.freedesktop.org/show_bug.cgi?id=48652
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Acked-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Signed-Off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/i915/intel_fb.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -283,6 +283,8 @@ void intel_fb_restore_mode(struct drm_de
 	struct drm_mode_config *config = &dev->mode_config;
 	struct drm_plane *plane;
 
+	mutex_lock(&dev->mode_config.mutex);
+
 	ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
 	if (ret)
 		DRM_DEBUG("failed to restore crtc mode\n");
@@ -290,4 +292,6 @@ void intel_fb_restore_mode(struct drm_de
 	/* Be sure to shut off any planes that may be active */
 	list_for_each_entry(plane, &config->plane_list, head)
 		plane->funcs->disable_plane(plane);
+
+	mutex_unlock(&dev->mode_config.mutex);
 }


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/