From patchwork Thu Jul 8 13:22:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dennis Rachui X-Patchwork-Id: 12365235 X-Patchwork-Delegate: kieran@bingham.xyz 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=-17.0 required=3.0 tests=BAYES_00, 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 E5A7DC07E96 for ; Thu, 8 Jul 2021 13:33:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C09A0616E8 for ; Thu, 8 Jul 2021 13:33:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230388AbhGHNgI (ORCPT ); Thu, 8 Jul 2021 09:36:08 -0400 Received: from smtp1.de.adit-jv.com ([93.241.18.167]:41158 "EHLO smtp1.de.adit-jv.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229901AbhGHNgH (ORCPT ); Thu, 8 Jul 2021 09:36:07 -0400 X-Greylist: delayed 569 seconds by postgrey-1.27 at vger.kernel.org; Thu, 08 Jul 2021 09:36:07 EDT Received: from hi2exch02.adit-jv.com (hi2exch02.adit-jv.com [10.72.92.28]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp1.de.adit-jv.com (Postfix) with ESMTPS id 75D6A3C003F; Thu, 8 Jul 2021 15:23:53 +0200 (CEST) Received: from vmlxhi-082.localdomain (10.72.92.227) by hi2exch02.adit-jv.com (10.72.92.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.14; Thu, 8 Jul 2021 15:23:53 +0200 From: Dennis Rachui To: CC: , Steve Longerbeam , Mauro Carvalho Chehab , Maxime Ripard , Sakari Ailus , Laurent Pinchart , , , Subject: [PATCH] media: rcar-csi2: do not update format while streaming Date: Thu, 8 Jul 2021 15:22:58 +0200 Message-ID: <1625750578-108454-1-git-send-email-drachui@de.adit-jv.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Originating-IP: [10.72.92.227] X-ClientProxiedBy: hi2exch02.adit-jv.com (10.72.92.28) To hi2exch02.adit-jv.com (10.72.92.28) Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Verify that streaming is not active before setting the pad format. According to the VIDIOC documentation [1] changes to the active format of a media pad via the VIDIOC_SUBDEV_S_FMT ioctl are applied to the underlying hardware. In rcar-csi2 a format change only applies to hardware, when the pipeline is started. While the device is not in use, it is therefore okay to update the format. However, when the pipeline is active, this leads to a format mismatch between driver and device. Other applications can query the format with VIDIOC_SUBDEV_G_FMT at any time and would be reported a format that does not fit the current stream. This commit prevents format update while streaming is active and returns -EBUSY to user space, as suggested by [1]. [1] Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst Note: after creation of this commit, it was noticed that Steve Longerbeam has a very similar solution in his fork. Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver") Cc: Steve Longerbeam Signed-off-by: Dennis Rachui --- drivers/media/platform/rcar-vin/rcar-csi2.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c index e28eff0..98152e1 100644 --- a/drivers/media/platform/rcar-vin/rcar-csi2.c +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c @@ -724,18 +724,37 @@ static int rcsi2_set_pad_format(struct v4l2_subdev *sd, { struct rcar_csi2 *priv = sd_to_csi2(sd); struct v4l2_mbus_framefmt *framefmt; + int ret = 0; + + mutex_lock(&priv->lock); if (!rcsi2_code_to_fmt(format->format.code)) format->format.code = rcar_csi2_formats[0].code; if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) { + + /* + * Do not apply changes to active format while streaming. + * + * Since video streams could be forwarded from sink pad to any + * source pad (depending on CSI-2 channel routing), all + * media pads are effected by this rule. + */ + if (priv->stream_count > 0) { + ret = -EBUSY; + goto out; + } + priv->mf = format->format; } else { framefmt = v4l2_subdev_get_try_format(sd, sd_state, 0); *framefmt = format->format; } - return 0; +out: + mutex_unlock(&priv->lock); + + return ret; } static int rcsi2_get_pad_format(struct v4l2_subdev *sd,