1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 04d3fd3658f3..158d8e51db3d 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -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;
 }