drm/i915: use drm_modeset_lock_all

Two exceptions:
- debugfs files only read information which is not related to crtc, so
  can stay on the modeset_config lock.
- Same holds for the edp vdd work in intel_dp.c. Add a corresponding
  WARN_ON and a comment next to the intel_dp struct fields for
  documentation.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index d7bc817..5be09d1 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -1045,13 +1045,13 @@
 	}
 
 	if (!(put_image_rec->flags & I915_OVERLAY_ENABLE)) {
-		mutex_lock(&dev->mode_config.mutex);
+		drm_modeset_lock_all(dev);
 		mutex_lock(&dev->struct_mutex);
 
 		ret = intel_overlay_switch_off(overlay);
 
 		mutex_unlock(&dev->struct_mutex);
-		mutex_unlock(&dev->mode_config.mutex);
+		drm_modeset_unlock_all(dev);
 
 		return ret;
 	}
@@ -1075,7 +1075,7 @@
 		goto out_free;
 	}
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	mutex_lock(&dev->struct_mutex);
 
 	if (new_bo->tiling_mode) {
@@ -1157,7 +1157,7 @@
 		goto out_unlock;
 
 	mutex_unlock(&dev->struct_mutex);
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 
 	kfree(params);
 
@@ -1165,7 +1165,7 @@
 
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 	drm_gem_object_unreference_unlocked(&new_bo->base);
 out_free:
 	kfree(params);
@@ -1241,7 +1241,7 @@
 		return -ENODEV;
 	}
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	mutex_lock(&dev->struct_mutex);
 
 	ret = -EINVAL;
@@ -1307,7 +1307,7 @@
 	ret = 0;
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 
 	return ret;
 }