From patchwork Wed Sep 1 12:46:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Cai,Huoqing" X-Patchwork-Id: 505342 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB825C43214 for ; Wed, 1 Sep 2021 12:49:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE70D60E98 for ; Wed, 1 Sep 2021 12:49:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344446AbhIAMuq (ORCPT ); Wed, 1 Sep 2021 08:50:46 -0400 Received: from mx20.baidu.com ([111.202.115.85]:43616 "EHLO baidu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1345514AbhIAMrz (ORCPT ); Wed, 1 Sep 2021 08:47:55 -0400 Received: from BC-Mail-Ex22.internal.baidu.com (unknown [172.31.51.16]) by Forcepoint Email with ESMTPS id 9975EBDFBB94475CD40E; Wed, 1 Sep 2021 20:46:56 +0800 (CST) Received: from BJHW-MAIL-EX27.internal.baidu.com (10.127.64.42) by BC-Mail-Ex22.internal.baidu.com (172.31.51.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2242.12; Wed, 1 Sep 2021 20:46:56 +0800 Received: from LAPTOP-UKSR4ENP.internal.baidu.com (172.31.63.8) by BJHW-MAIL-EX27.internal.baidu.com (10.127.64.42) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Wed, 1 Sep 2021 20:46:56 +0800 From: Cai Huoqing To: CC: Mauro Carvalho Chehab , , Subject: [PATCH v3] usb: stkwebcam: Update the reference count of the usb device structure Date: Wed, 1 Sep 2021 20:46:49 +0800 Message-ID: <20210901124650.31653-1-caihuoqing@baidu.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [172.31.63.8] X-ClientProxiedBy: BJHW-Mail-Ex07.internal.baidu.com (10.127.64.17) To BJHW-MAIL-EX27.internal.baidu.com (10.127.64.42) Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Use usb_get_dev() to increment the reference count of the usb device structure in order to avoid releasing the structure while it is still in use. And use usb_put_dev() to decrement the reference count and thus, when it will be equal to 0 the structure will be released. Signed-off-by: Cai Huoqing --- v2->v3: *call usb_put_dev() in the error path of stk_camera_probe *move v4l2_ctrl_handler_free/v4l2_device_unregister/kfree(dev) from stk_camera_disconnect() to stk_v4l_dev_release() drivers/media/usb/stkwebcam/stk-webcam.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c index 0e231e576dc3..9f445e6ab5fa 100644 --- a/drivers/media/usb/stkwebcam/stk-webcam.c +++ b/drivers/media/usb/stkwebcam/stk-webcam.c @@ -1234,6 +1234,11 @@ static void stk_v4l_dev_release(struct video_device *vd) if (dev->sio_bufs != NULL || dev->isobufs != NULL) pr_err("We are leaking memory\n"); usb_put_intf(dev->interface); + usb_put_dev(dev->udev); + + v4l2_ctrl_handler_free(&dev->hdl); + v4l2_device_unregister(&dev->v4l2_dev); + kfree(dev); } static const struct video_device stk_v4l_data = { @@ -1309,7 +1314,7 @@ static int stk_camera_probe(struct usb_interface *interface, init_waitqueue_head(&dev->wait_frame); dev->first_init = 1; /* webcam LED management */ - dev->udev = udev; + dev->udev = usb_get_dev(udev); dev->interface = interface; usb_get_intf(interface); @@ -1365,6 +1370,7 @@ static int stk_camera_probe(struct usb_interface *interface, error_put: usb_put_intf(interface); + usb_put_dev(dev->udev); error: v4l2_ctrl_handler_free(hdl); v4l2_device_unregister(&dev->v4l2_dev); @@ -1385,9 +1391,6 @@ static void stk_camera_disconnect(struct usb_interface *interface) video_device_node_name(&dev->vdev)); video_unregister_device(&dev->vdev); - v4l2_ctrl_handler_free(&dev->hdl); - v4l2_device_unregister(&dev->v4l2_dev); - kfree(dev); } #ifdef CONFIG_PM