From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 197CCC433F5 for ; Sun, 20 Mar 2022 19:48:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343594AbiCTTuP (ORCPT ); Sun, 20 Mar 2022 15:50:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231210AbiCTTuO (ORCPT ); Sun, 20 Mar 2022 15:50:14 -0400 Received: from netrider.rowland.org (netrider.rowland.org [192.131.102.5]) by lindbergh.monkeyblade.net (Postfix) with SMTP id 65EAD275FC for ; Sun, 20 Mar 2022 12:48:51 -0700 (PDT) Received: (qmail 78219 invoked by uid 1000); 20 Mar 2022 15:48:50 -0400 Date: Sun, 20 Mar 2022 15:48:50 -0400 From: Alan Stern To: Felipe Balbi , Greg KH Cc: USB mailing list Subject: [RFC PATCH 2/4] USB: gadget: Register udc before gadget Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In preparation for adding a "gadget" bus, this patch reverses the order of registration of udc and gadget devices in usb_add_gadget(). The current code adds the gadget device first, probably because that was more convenient at the time and the order didn't really matter. But with the upcoming change, adding the gadget will cause driver probing to occur. Unwinding that on the error pathway will become much more obtrusive, not to mention the fact that a gadget driver might not work properly before the udc is registered. It's better to register the udc device first, particularly since that doesn't involve a bus or driver binding and therefore is simpler to unwind. For symmetry, the order of unregistration in usb_del_gadget() is likewise reversed. Signed-off-by: Alan Stern --- drivers/usb/gadget/udc/core.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) Index: usb-devel/drivers/usb/gadget/udc/core.c =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/core.c +++ usb-devel/drivers/usb/gadget/udc/core.c @@ -1308,10 +1308,6 @@ int usb_add_gadget(struct usb_gadget *ga if (ret) goto err_put_udc; - ret = device_add(&gadget->dev); - if (ret) - goto err_put_udc; - udc->gadget = gadget; gadget->udc = udc; @@ -1327,15 +1323,22 @@ int usb_add_gadget(struct usb_gadget *ga usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED); udc->vbus = true; + ret = device_add(&gadget->dev); + if (ret) + goto err_del_udc; + /* pick up one of pending gadget drivers */ ret = check_pending_gadget_drivers(udc); if (ret) - goto err_del_udc; + goto err_del_gadget; mutex_unlock(&udc_lock); return 0; + err_del_gadget: + device_del(&gadget->dev); + err_del_udc: flush_work(&gadget->work); device_del(&udc->dev); @@ -1344,8 +1347,6 @@ int usb_add_gadget(struct usb_gadget *ga list_del(&udc->list); mutex_unlock(&udc_lock); - device_del(&gadget->dev); - err_put_udc: put_device(&udc->dev); @@ -1469,8 +1470,8 @@ void usb_del_gadget(struct usb_gadget *g kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); flush_work(&gadget->work); - device_unregister(&udc->dev); device_del(&gadget->dev); + device_unregister(&udc->dev); } EXPORT_SYMBOL_GPL(usb_del_gadget);