1 files changed, 29 insertions, 10 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index be0f2d65db3a..0c6e25e979dd 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -305,6 +305,24 @@ void drm_fb_helper_restore(void)
 }
 EXPORT_SYMBOL(drm_fb_helper_restore);
 
+static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
+{
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_crtc *crtc;
+	int bound = 0, crtcs_bound = 0;
+
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		if (crtc->fb)
+			crtcs_bound++;
+		if (crtc->fb == fb_helper->fb)
+			bound++;
+	}
+
+	if (bound < crtcs_bound)
+		return false;
+	return true;
+}
+
 #ifdef CONFIG_MAGIC_SYSRQ
 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 {
@@ -338,6 +356,11 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 	 * For each CRTC in this fb, turn the connectors on/off.
 	 */
 	drm_modeset_lock_all(dev);
+	if (!drm_fb_helper_is_bound(fb_helper)) {
+		drm_modeset_unlock_all(dev);
+		return;
+	}
+
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		crtc = fb_helper->crtc_info[i].mode_set.crtc;
 
@@ -702,6 +725,11 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 	int i;
 
 	drm_modeset_lock_all(dev);
+	if (!drm_fb_helper_is_bound(fb_helper)) {
+		drm_modeset_unlock_all(dev);
+		return -EBUSY;
+	}
+
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		crtc = fb_helper->crtc_info[i].mode_set.crtc;
 
@@ -1369,21 +1397,12 @@ 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;
-	int bound = 0, crtcs_bound = 0;
-	struct drm_crtc *crtc;
 
 	if (!fb_helper->fb)
 		return 0;
 
 	drm_modeset_lock_all(dev);
-	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-		if (crtc->fb)
-			crtcs_bound++;
-		if (crtc->fb == fb_helper->fb)
-			bound++;
-	}
-
-	if (bound < crtcs_bound) {
+	if (!drm_fb_helper_is_bound(fb_helper)) {
 		fb_helper->delayed_hotplug = true;
 		drm_modeset_unlock_all(dev);
 		return 0;