Merge tag 'topic/core-stuff-2014-05-05' of git://anongit.freedesktop.org/drm-intel into drm-next

Update pull request with drm core patches. Mostly some polish for the
primary plane stuff and a pile of patches all over from Thierry. Has
survived a few days in drm-intel-nightly without causing ill.

I've frobbed my scripts a bit to also tag my topic branches so that you
have something stable to pull - I've accidentally pushed a bunch more
patches onto this branch before you've taken the old pull request.

* tag 'topic/core-stuff-2014-05-05' of git://anongit.freedesktop.org/drm-intel:
  drm: Make drm_crtc_helper_disable() return void
  drm: Fix indentation of closing brace
  drm/dp: Fix typo in comment
  drm: Fixup flip-work kerneldoc
  drm/fb: Fix typos
  drm/edid: Cleanup kerneldoc
  drm/edid: Drop revision argument for drm_mode_std()
  drm: Try to acquire modeset lock on panic or sysrq
  drm: remove unused argument from drm_open_helper
  drm: Handle ->disable_plane failures correctly
  drm: Simplify fb refcounting rules around ->update_plane
  drm/crtc-helper: gc usless connector loop in disable_unused_functions
  drm/plane_helper: don't disable plane in destroy function
  drm/plane-helper: Fix primary plane scaling check
  drm: make mode_valid callback optional
  drm/edid: Fill PAR in AVI infoframe based on CEA mode list

1 files changed, 13 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 04d3fd3658f3..e95ed5805f07 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -45,13 +45,13 @@ static LIST_HEAD(kernel_fb_helper_list);
  * DOC: fbdev helpers
  *
  * The fb helper functions are useful to provide an fbdev on top of a drm kernel
- * mode setting driver. They can be used mostly independantely from the crtc
+ * mode setting driver. They can be used mostly independently from the crtc
  * helper functions used by many drivers to implement the kernel mode setting
  * interfaces.
  *
  * Initialization is done as a three-step process with drm_fb_helper_init(),
  * drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config().
- * Drivers with fancier requirements than the default beheviour can override the
+ * Drivers with fancier requirements than the default behaviour can override the
  * second step with their own code.  Teardown is done with drm_fb_helper_fini().
  *
  * At runtime drivers should restore the fbdev console by calling
@@ -59,7 +59,7 @@ static LIST_HEAD(kernel_fb_helper_list);
  * should also notify the fb helper code from updates to the output
  * configuration by calling drm_fb_helper_hotplug_event(). For easier
  * integration with the output polling code in drm_crtc_helper.c the modeset
- * code proves a ->output_poll_changed callback.
+ * code provides a ->output_poll_changed callback.
  *
  * All other functions exported by the fb helper library can be used to
  * implement the fbdev driver interface by the driver.
@@ -326,12 +326,21 @@ static bool drm_fb_helper_force_kernel_mode(void)
 		return false;
 
 	list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
-		if (helper->dev->switch_power_state == DRM_SWITCH_POWER_OFF)
+		struct drm_device *dev = helper->dev;
+
+		if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
+			continue;
+
+		if (!mutex_trylock(&dev->mode_config.mutex)) {
+			error = true;
 			continue;
+		}
 
 		ret = drm_fb_helper_restore_fbdev_mode(helper);
 		if (ret)
 			error = true;
+
+		mutex_unlock(&dev->mode_config.mutex);
 	}
 	return error;
 }