{"id":20993,"url":"https://patchwork.libcamera.org/api/patches/20993/?format=json","web_url":"https://patchwork.libcamera.org/patch/20993/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20240822153527.25320-5-laurent.pinchart+renesas@ideasonboard.com>","date":"2024-08-22T15:35:24","name":"[v2,4/7] media: v4l2-subdev: Refactor warnings in v4l2_subdev_link_validate()","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"68982c452864bbd0a2d1d5dd7d8110a56b3a679f","submitter":{"id":204,"url":"https://patchwork.libcamera.org/api/people/204/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart+renesas@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/20993/mbox/","series":[{"id":4533,"url":"https://patchwork.libcamera.org/api/series/4533/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=4533","date":"2024-08-22T15:35:20","name":"media: v4l2: Improve media link validation","version":2,"mbox":"https://patchwork.libcamera.org/series/4533/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/20993/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/20993/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id B1B44C323E\n\tfor ;\n\tThu, 22 Aug 2024 15:35:43 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 0CEC3633D1;\n\tThu, 22 Aug 2024 17:35:43 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 83412633CF\n\tfor ;\n\tThu, 22 Aug 2024 17:35:36 +0200 (CEST)","from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi\n\t[81.175.209.231])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id BD3B51083;\n\tThu, 22 Aug 2024 17:34:32 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ZO+znxHn\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1724340872;\n\tbh=L6PW/jnfXa4+nyLEP2SbfgQft2F4O8LsNw4OqltCe/g=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=ZO+znxHn3QUDNjcqbTqpq5ynt1/dPTE2hJtRe/CxAqN3qTvmEwQOdWsZBUcucydF2\n\tzwQ90wAJuGORKewyOgycAP7hT2SqYnLS6qLd08JcWiMHip3QwfkO30trLNUHD7FUgC\n\tKOC5ntjV3Uq7n6yQcih78sejBZ7AzISFoIdO0lEA=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Cc":"Chen-Yu Tsai , Eugen Hristev ,\n\tHans Verkuil ,\n\tJacopo Mondi ,\n\tKieran Bingham ,\n\tMaxime Ripard , Sakari Ailus ,\n\tTomi Valkeinen ,\n\tlinux-renesas-soc@vger.kernel.org, linux-sunxi@lists.linux.dev","Subject":"[PATCH v2 4/7] media: v4l2-subdev: Refactor warnings in\n\tv4l2_subdev_link_validate()","Date":"Thu, 22 Aug 2024 18:35:24 +0300","Message-ID":"<20240822153527.25320-5-laurent.pinchart+renesas@ideasonboard.com>","X-Mailer":"git-send-email 2.44.2","In-Reply-To":"<20240822153527.25320-1-laurent.pinchart+renesas@ideasonboard.com>","References":"<20240822153527.25320-1-laurent.pinchart+renesas@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"The v4l2_subdev_link_validate() function prints a one-time warning if it\ngets called on a link whose source or sink is not a subdev. As links get\nvalidated in the context of their sink, a call to the helper when the\nlink's sink is not a subdev indicates that the driver has set its\n.link_validate() handler to v4l2_subdev_link_validate() on a non-subdev\nentity, which is a clear driver bug. On the other hand, the link's\nsource not being a subdev indicates that the helper is used for a subdev\nconnected to a video output device, which is a lesser issue, if only\nbecause this is currently common practice.\n\nThere are no drivers left in the kernel that use\nv4l2_subdev_link_validate() in a context where it may get called on a\nnon-subdev sink. Replace the pr_warn_once() with a WARN_ON_ONCE() in\nthis case to make sure that new offenders won't be introduced.\n\nSigned-off-by: Laurent Pinchart \n---\nChanges since v1:\n\n- Switch from WARN_ON() to WARN_ON_ONCE()\n---\n drivers/media/v4l2-core/v4l2-subdev.c | 14 +++++++++-----\n 1 file changed, 9 insertions(+), 5 deletions(-)","diff":"diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c\nindex 7c5812d55315..d3196042d5c5 100644\n--- a/drivers/media/v4l2-core/v4l2-subdev.c\n+++ b/drivers/media/v4l2-core/v4l2-subdev.c\n@@ -1443,11 +1443,15 @@ int v4l2_subdev_link_validate(struct media_link *link)\n \tbool states_locked;\n \tint ret;\n \n-\tif (!is_media_entity_v4l2_subdev(link->sink->entity) ||\n-\t !is_media_entity_v4l2_subdev(link->source->entity)) {\n-\t\tpr_warn_once(\"%s of link '%s':%u->'%s':%u is not a V4L2 sub-device, driver bug!\\n\",\n-\t\t\t !is_media_entity_v4l2_subdev(link->sink->entity) ?\n-\t\t\t \"sink\" : \"source\",\n+\t/*\n+\t * Links are validated in the context of the sink entity. Usage of this\n+\t * helper on a sink that is not a subdev is a clear driver bug.\n+\t */\n+\tif (WARN_ON_ONCE(!is_media_entity_v4l2_subdev(link->sink->entity)))\n+\t\treturn -EINVAL;\n+\n+\tif (!is_media_entity_v4l2_subdev(link->source->entity)) {\n+\t\tpr_warn_once(\"source of link '%s':%u->'%s':%u is not a V4L2 sub-device, driver bug!\\n\",\n \t\t\t link->source->entity->name, link->source->index,\n \t\t\t link->sink->entity->name, link->sink->index);\n \t\treturn 0;\n","prefixes":["v2","4/7"]}