diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index bc37c65305d48604dc4be857a37ff29b55fbf44f..037d389ab630dee28319771d12d46d31d0479ec3 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -290,7 +290,6 @@ struct drm_device *ast_device_create(struct pci_dev *pdev,
 	ast->regs = regs;
 	ast->ioregs = ioregs;
 
-	ast_detect_widescreen(ast);
 	ast_detect_tx_chip(ast, need_post);
 
 	ret = ast_get_dram_info(ast);
@@ -315,6 +314,8 @@ struct drm_device *ast_device_create(struct pci_dev *pdev,
 			drm_info(dev, "failed to map reserved buffer!\n");
 	}
 
+	ast_detect_widescreen(ast);
+
 	ret = ast_mode_config_init(ast);
 	if (ret)
 		return ERR_PTR(ret);