1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index b7021069b078..e79c8d3700d8 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3400,7 +3400,16 @@ void drm_fb_release(struct drm_file *priv)
         struct drm_device *dev = priv->minor->dev;
         struct drm_framebuffer *fb, *tfb;
 
-        mutex_lock(&priv->fbs_lock);
+        /*
+         * When the file gets released that means no one else can access the fb
+         * list any more, so no need to grab fpriv->fbs_lock. And we need to to
+         * avoid upsetting lockdep since the universal cursor code adds a
+         * framebuffer while holding mutex locks.
+         *
+         * Note that a real deadlock between fpriv->fbs_lock and the modeset
+         * locks is impossible here since no one else but this function can get
+         * at it any more.
+         */
         list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
 
                 mutex_lock(&dev->mode_config.fb_lock);
@@ -3413,7 +3422,6 @@ void drm_fb_release(struct drm_file *priv)
                 /* This will also drop the fpriv->fbs reference. */
                 drm_framebuffer_remove(fb);
         }
-        mutex_unlock(&priv->fbs_lock);
 }
 
 /**