diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c
index 56483860306b..a4a23b9623ad 100644
--- a/drivers/gpu/drm/ast/ast_dp.c
+++ b/drivers/gpu/drm/ast/ast_dp.c
@@ -190,6 +190,7 @@ void ast_dp_set_on_off(struct drm_device *dev, bool on)
 {
 	struct ast_private *ast = to_ast_private(dev);
 	u8 video_on_off = on;
+	u32 i = 0;
 
 	// Video On/Off
 	ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xE3, (u8) ~AST_DP_VIDEO_ENABLE, on);
@@ -202,6 +203,8 @@ void ast_dp_set_on_off(struct drm_device *dev, bool on)
 						ASTDP_MIRROR_VIDEO_ENABLE) != video_on_off) {
 			// wait 1 ms
 			mdelay(1);
+			if (++i > 200)
+				break;
 		}
 	}
 }