1 files changed, 42 insertions, 11 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 95072047396..140b9525b48 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -342,9 +342,22 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 
+bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
+{
+        bool error = false;
+        int i, ret;
+        for (i = 0; i < fb_helper->crtc_count; i++) {
+                struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
+                ret = drm_crtc_helper_set_config(mode_set);
+                if (ret)
+                        error = true;
+        }
+        return error;
+}
+EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode);
+
 bool drm_fb_helper_force_kernel_mode(void)
 {
-        int i = 0;
         bool ret, error = false;
         struct drm_fb_helper *helper;
 
@@ -352,12 +365,12 @@ bool drm_fb_helper_force_kernel_mode(void)
                 return false;
 
         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
-                for (i = 0; i < helper->crtc_count; i++) {
-                        struct drm_mode_set *mode_set = &helper->crtc_info[i].mode_set;
-                        ret = drm_crtc_helper_set_config(mode_set);
-                        if (ret)
-                                error = true;
-                }
+                if (helper->dev->switch_power_state == DRM_SWITCH_POWER_OFF)
+                        continue;
+
+                ret = drm_fb_helper_restore_fbdev_mode(helper);
+                if (ret)
+                        error = true;
         }
         return error;
 }
@@ -1503,17 +1516,33 @@ bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
 }
 EXPORT_SYMBOL(drm_fb_helper_initial_config);
 
-bool drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
+/**
+ * drm_fb_helper_hotplug_event - respond to a hotplug notification by
+ *                               probing all the outputs attached to the fb.
+ * @fb_helper: the drm_fb_helper
+ *
+ * LOCKING:
+ * Called at runtime, must take mode config lock.
+ *
+ * Scan the connectors attached to the fb_helper and try to put together a
+ * setup after *notification of a change in output configuration.
+ *
+ * RETURNS:
+ * 0 on success and a non-zero error code otherwise.
+ */
+int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 {
+        struct drm_device *dev = fb_helper->dev;
         int count = 0;
         u32 max_width, max_height, bpp_sel;
         bool bound = false, crtcs_bound = false;
         struct drm_crtc *crtc;
 
         if (!fb_helper->fb)
-                return false;
+                return 0;
 
-        list_for_each_entry(crtc, &fb_helper->dev->mode_config.crtc_list, head) {
+        mutex_lock(&dev->mode_config.mutex);
+        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                 if (crtc->fb)
                         crtcs_bound = true;
                 if (crtc->fb == fb_helper->fb)
@@ -1522,7 +1551,8 @@ bool drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 
         if (!bound && crtcs_bound) {
                 fb_helper->delayed_hotplug = true;
-                return false;
+                mutex_unlock(&dev->mode_config.mutex);
+                return 0;
         }
         DRM_DEBUG_KMS("\n");
 
@@ -1533,6 +1563,7 @@ bool drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
         count = drm_fb_helper_probe_connector_modes(fb_helper, max_width,
                                                     max_height);
         drm_setup_crtcs(fb_helper);
+        mutex_unlock(&dev->mode_config.mutex);
 
         return drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
 }