From patchwork Thu Jan 7 22:54:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 12005275 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 3ECEAC433E6 for ; Thu, 7 Jan 2021 22:56:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00E4B235FF for ; Thu, 7 Jan 2021 22:55:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727933AbhAGWz7 (ORCPT ); Thu, 7 Jan 2021 17:55:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727865AbhAGWz7 (ORCPT ); Thu, 7 Jan 2021 17:55:59 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB699C0612F4 for ; Thu, 7 Jan 2021 14:55:18 -0800 (PST) Received: from pendragon.lan (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 22E67292; Thu, 7 Jan 2021 23:55:14 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1610060114; bh=u0z/eHyxvJRXLde5MI9DBhuv+3C5sM+VaCS08W/RFuI=; h=From:To:Cc:Subject:Date:From; b=dYnoYs+NVu4scVr/va6DaLXXzgqWOLRc+/duy5zkdt+/g2jTjs4sImFTi/PEMfWp2 NKBuOD+bWbiDwhwUq3Ynr9LUnay+i80VgX1gdPS8c9H2BiRA0g2l/1gcyZi6gxKsAt R3FFy3y4j2GgJvuZuvP8ZoaRRg/qV97WFa/BzIF0= From: Laurent Pinchart To: linux-media@vger.kernel.org Cc: Sakari Ailus , Laurent Pinchart Subject: [PATCH] media: v4l2-async: Safely unregister an non-registered async subdev Date: Fri, 8 Jan 2021 00:54:58 +0200 Message-Id: <20210107225458.4485-1-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Laurent Pinchart Make the V4L2 async framework a bit more robust by allowing to unregister a non-registered async subdev. Otherwise the v4l2_async_cleanup() will attempt to delete the async subdev from the subdev_list with the corresponding list_head not initialized. Signed-off-by: Laurent Pinchart Reviewed-by: Kieran Bingham --- drivers/media/v4l2-core/v4l2-async.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index 8bde33c21ce4..fc4525c4a75f 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -750,6 +750,9 @@ EXPORT_SYMBOL(v4l2_async_register_subdev); void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) { + if (!sd->async_list.next) + return; + mutex_lock(&list_lock); __v4l2_async_notifier_unregister(sd->subdev_notifier);