drm/ast: Managed release of ast firmware

The ast driver loads firmware for the DP501 display encoder. The
patch replaces the removal code with a managed release function.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200730135206.30239-8-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_dp501.c

@@ -8,11 +8,24 @@
 
 MODULE_FIRMWARE("ast_dp501_fw.bin");
 
+static void ast_release_firmware(void *data)
+{
+	struct ast_private *ast = data;
+
+	release_firmware(ast->dp501_fw);
+	ast->dp501_fw = NULL;
+}
+
 static int ast_load_dp501_microcode(struct drm_device *dev)
 {
 	struct ast_private *ast = to_ast_private(dev);
+	int ret;
+
+	ret = request_firmware(&ast->dp501_fw, "ast_dp501_fw.bin", dev->dev);
+	if (ret)
+		return ret;
 
-	return request_firmware(&ast->dp501_fw, "ast_dp501_fw.bin", dev->dev);
+	return devm_add_action_or_reset(dev->dev, ast_release_firmware, ast);
 }
 
 static void send_ack(struct ast_private *ast)
@@ -435,11 +448,3 @@ void ast_init_3rdtx(struct drm_device *dev)
 		}
 	}
 }
-
-void ast_release_firmware(struct drm_device *dev)
-{
-	struct ast_private *ast = to_ast_private(dev);
-
-	release_firmware(ast->dp501_fw);
-	ast->dp501_fw = NULL;
-}

drivers/gpu/drm/ast/ast_drv.h

@@ -312,7 +312,6 @@ bool ast_backup_fw(struct drm_device *dev, u8 *addr, u32 size);
 bool ast_dp501_read_edid(struct drm_device *dev, u8 *ediddata);
 u8 ast_get_dp501_max_clk(struct drm_device *dev);
 void ast_init_3rdtx(struct drm_device *dev);
-void ast_release_firmware(struct drm_device *dev);
 
 /* ast_cursor.c */
 int ast_cursor_init(struct ast_private *ast);

drivers/gpu/drm/ast/ast_main.c

@@ -442,11 +442,8 @@ struct ast_private *ast_device_create(struct drm_driver *drv,
 
 void ast_device_destroy(struct ast_private *ast)
 {
-	struct drm_device *dev = &ast->base;
-
 	/* enable standard VGA decode */
 	ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa1, 0x04);
 
-	ast_release_firmware(dev);
 	kfree(ast->dp501_fw_addr);
 }