From patchwork Wed Jul 22 09:46:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bastien Nocera X-Patchwork-Id: 11677999 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BB58113B4 for ; Wed, 22 Jul 2020 09:46:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC1D620787 for ; Wed, 22 Jul 2020 09:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731875AbgGVJqe (ORCPT ); Wed, 22 Jul 2020 05:46:34 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:59691 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731833AbgGVJqb (ORCPT ); Wed, 22 Jul 2020 05:46:31 -0400 Received: from localhost.localdomain (lns-bzn-39-82-255-60-242.adsl.proxad.net [82.255.60.242]) (Authenticated sender: hadess@hadess.net) by relay12.mail.gandi.net (Postfix) with ESMTPSA id EAAA1200008; Wed, 22 Jul 2020 09:46:28 +0000 (UTC) From: Bastien Nocera To: linux-usb@vger.kernel.org Cc: Greg Kroah-Hartman , Alan Stern , Bastien Nocera Subject: [PATCH 1/2] USB: Fix device driver race Date: Wed, 22 Jul 2020 11:46:27 +0200 Message-Id: <20200722094628.4236-1-hadess@hadess.net> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When a new device with a specialised device driver is plugged in, the new driver will be modprobe()'d but the driver core will attach the "generic" driver to the device. After that, nothing will trigger a reprobe when the modprobe()'d device driver has finished initialising, as the device has the "generic" driver attached to it. Trigger a reprobe ourselves when new specialised drivers get registered. Signed-off-by: Bastien Nocera --- drivers/usb/core/driver.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index f81606c6a35b..a6187dd2186c 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -905,6 +905,30 @@ static int usb_uevent(struct device *dev, struct kobj_uevent_env *env) return 0; } +static int __usb_bus_reprobe_drivers(struct device *dev, void *data) +{ + struct usb_device_driver *udriver = to_usb_device_driver(dev->driver); + struct usb_device *udev = to_usb_device(dev); + + if (udriver == &usb_generic_driver && + !udev->use_generic_driver) + return device_reprobe(dev); + + return 0; +} + +static int __usb_device_driver_added(struct device_driver *drv, void *data) +{ + struct usb_device_driver *udrv = to_usb_device_driver(drv); + + if (udrv->match) { + bus_for_each_dev(&usb_bus_type, NULL, udrv, + __usb_bus_reprobe_drivers); + } + + return 0; +} + /** * usb_register_device_driver - register a USB device (not interface) driver * @new_udriver: USB operations for the device driver @@ -934,13 +958,16 @@ int usb_register_device_driver(struct usb_device_driver *new_udriver, retval = driver_register(&new_udriver->drvwrap.driver); - if (!retval) + if (!retval) { + bus_for_each_drv(&usb_bus_type, NULL, NULL, + __usb_device_driver_added); pr_info("%s: registered new device driver %s\n", usbcore_name, new_udriver->name); - else + } else { printk(KERN_ERR "%s: error %d registering device " " driver %s\n", usbcore_name, retval, new_udriver->name); + } return retval; }