From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E1A30C433DF for ; Mon, 25 May 2020 09:23:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C04422071A for ; Mon, 25 May 2020 09:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389379AbgEYJXy (ORCPT ); Mon, 25 May 2020 05:23:54 -0400 Received: from mga09.intel.com ([134.134.136.24]:33917 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389105AbgEYJXx (ORCPT ); Mon, 25 May 2020 05:23:53 -0400 IronPort-SDR: wBxnwV5W+OHiayKKCT1YN0IIZjM5slNd82jjFo42adQtyvUj9rp2mPspKFs58YMNIkFQwBNIvG pJhZVfHX7J0A== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2020 02:23:53 -0700 IronPort-SDR: 8T+EYlekXW81YDnfQxgXmNPP4+sZpiz5bOQmWREGy7U1kHCX1wzKMUyAi2yCUsafJl4+ho9slt jNT+gJIWlmvg== X-IronPort-AV: E=Sophos;i="5.73,432,1583222400"; d="scan'208";a="254861106" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2020 02:23:50 -0700 Received: by paasikivi.fi.intel.com (Postfix, from userid 1000) id F1EB620953; Mon, 25 May 2020 12:23:47 +0300 (EEST) Date: Mon, 25 May 2020 12:23:47 +0300 From: Sakari Ailus To: Dafna Hirschfeld Cc: linux-media@vger.kernel.org, laurent.pinchart@ideasonboard.com, helen.koike@collabora.com, ezequiel@collabora.com, hverkuil@xs4all.nl, kernel@collabora.com, dafna3@gmail.com, linux-rockchip@lists.infradead.org, mchehab@kernel.org, tfiga@chromium.org, skhan@linuxfoundation.org, niklas.soderlund@ragnatech.se--annotate Subject: Re: [PATCH v4 2/5] media: v4l2-common: add helper functions to call s_stream() callbacks Message-ID: <20200525092347.GD7618@paasikivi.fi.intel.com> References: <20200522075522.6190-1-dafna.hirschfeld@collabora.com> <20200522075522.6190-3-dafna.hirschfeld@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200522075522.6190-3-dafna.hirschfeld@collabora.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Dafna, My apologies for not reviewing this earlier. On Fri, May 22, 2020 at 09:55:19AM +0200, Dafna Hirschfeld wrote: > From: Helen Koike > > Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate > through the subdevices in a given stream (i.e following links from sink > to source) and call .s_stream() callback. > > If .s_stream(true) fails, call .s_stream(false) in the reverse order. > > Signed-off-by: Helen Koike > Signed-off-by: Dafna Hirschfeld > --- > drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++ > include/media/v4l2-common.h | 39 +++++++++++ > 2 files changed, 138 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c > index 9e8eb45a5b03..734db2bf5ca9 100644 > --- a/drivers/media/v4l2-core/v4l2-common.c > +++ b/drivers/media/v4l2-core/v4l2-common.c > @@ -442,3 +442,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat, > return 0; > } > EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt); > + > +#if defined(CONFIG_MEDIA_CONTROLLER) > + > +/* > + * v4l2_pipeline_subdevs_get - Assemble a list of subdevices in a pipeline > + * @subdevs: the array to be filled. > + * @max_size: max number of elements that can fit in subdevs array. > + * > + * Walk from a video node, following links from sink to source and fill the > + * array with subdevices in the path. > + * The walker performs a depth-first traversal, which means that, in a topology > + * sd1->sd2->sd3->vdev, sd1 will be the first element placed in the array. > + * > + * Return the number of subdevices filled in the array. > + */ > +static int v4l2_pipeline_subdevs_get(struct video_device *vdev, > + struct v4l2_subdev **subdevs, > + unsigned int max_size) > +{ > + struct media_entity *entity = &vdev->entity; > + struct media_device *mdev = entity->graph_obj.mdev; > + struct media_graph graph; > + int idx = 0; > + int ret; > + > + ret = media_graph_walk_init(&graph, mdev); > + if (ret) > + return ret; > + > + media_graph_walk_start(&graph, entity); > + > + while ((entity = media_graph_walk_next_stream(&graph))) { > + if (!is_media_entity_v4l2_subdev(entity)) > + continue; > + if (WARN_ON(idx >= max_size)) > + return -EINVAL; > + subdevs[idx++] = media_entity_to_v4l2_subdev(entity); > + } > + > + media_graph_walk_cleanup(&graph); > + > + return idx; > +} > + > +static void v4l2_subdevs_stream_disable(struct v4l2_subdev **subdevs, int size) > +{ > + int i; > + > + for (i = 0; i < size; i++) { > + struct v4l2_subdev *sd = subdevs[i]; > + > + dev_dbg(sd->dev, > + "disabling stream for '%s'\n", sd->entity.name); > + v4l2_subdev_call(sd, video, s_stream, false); > + } > +} > + > +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev) > +{ > + struct media_device *mdev = vdev->entity.graph_obj.mdev; > + struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH]; > + struct v4l2_subdev *sd; > + int i, size, ret; > + > + size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs)); > + if (size <= 0) > + return size; > + > + /* Call s_stream() in reverse order to enable sensors last */ > + for (i = size - 1; i >= 0; i--) { > + sd = subdevs[i]; > + dev_dbg(mdev->dev, > + "enabling stream for '%s'\n", sd->entity.name); > + ret = v4l2_subdev_call(sd, video, s_stream, true); The s_stream callback is only called on the very next sub-device upstream in the pipeline, not on any further sub-devices. This is because a driver for the device knows best in which order things need to be set up. This could include, for instance, telling a sensor to place its CSI-2 transmitter to LP-11 state. > + if (ret && ret != -ENOIOCTLCMD) { > + v4l2_subdevs_stream_disable(subdevs + i + 1, > + size - i - 1); > + return ret; > + } > + } > + return 0; > +} > +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable); > + > +int v4l2_pipeline_stream_disable(struct video_device *vdev) > +{ > + struct v4l2_subdev *subdevs[MEDIA_ENTITY_ENUM_MAX_DEPTH]; > + int size; > + > + size = v4l2_pipeline_subdevs_get(vdev, subdevs, ARRAY_SIZE(subdevs)); > + if (size < 0) > + return size; > + > + v4l2_subdevs_stream_disable(subdevs, size); > + return 0; > +} > +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable); > + > +#endif /* CONFIG_MEDIA_CONTROLLER */ > diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h > index 150ee16ebd81..a278bcf3c5bc 100644 > --- a/include/media/v4l2-common.h > +++ b/include/media/v4l2-common.h > @@ -539,4 +539,43 @@ static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf, > buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC; > } > > +#if defined(CONFIG_MEDIA_CONTROLLER) > + > +/** > + * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream > + * @vdev: Starting video device. > + * > + * Call .s_stream(true) callback in all the subdevices participating in the > + * stream, i.e. following links from sink to source. > + * > + * .s_stream(true) is also called from sink to source, i.e. in a topology > + * sd1->sd2->sd3->vdev, .s_stream(true) of sd3 is called first. > + * > + * Calls to this function can be nested, in which case the same number of > + * v4l2_pipeline_stream_disable() calls will be required to disable streaming > + * through subdevices in the pipeline. > + * The pipeline pointer must be identical for all nested calls to > + * v4l2_pipeline_stream_enable(). > + */ > +__must_check int v4l2_pipeline_stream_enable(struct video_device *vdev); > + > +/** > + * v4l2_pipeline_stream_disable - Call .s_stream(false) callbacks in the stream > + * @vdev: Starting video device. > + * > + * Call .s_stream(false) callback in all the subdevices participating in the > + * stream, i.e. following links from sink to source. > + * > + * s_stream(false) is called in a reverse order from > + * v4l2_pipeline_stream_enable(), i.e. in a topology sd1->sd2->sd3->vdev, > + * .s_stream(false) of sd1 is called first. > + * > + * If multiple calls to v4l2_pipeline_stream_enable() have been made, the same > + * number of calls to this function are required to disable streaming through > + * subdevices in the pipeline. > + */ > +int v4l2_pipeline_stream_disable(struct video_device *vdev); > + > +#endif /* CONFIG_MEDIA_CONTROLLER */ > + > #endif /* V4L2_COMMON_H_ */ -- Kind regards, Sakari Ailus