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From:   Kaaira Gupta <kgupta@es.iitr.ac.in>
To:     Helen Koike <helen.koike@collabora.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Kieran Bingham <kieran.bingham@ideasonboard.com>
Cc:     Kaaira Gupta <kgupta@es.iitr.ac.in>
Subject: [PATCH v3 5/9] media: vimc: Separate closing of stream and thread
Date:   Wed, 19 Aug 2020 23:34:38 +0530
Message-Id: <20200819180442.11630-6-kgupta@es.iitr.ac.in>
In-Reply-To: <20200819180442.11630-1-kgupta@es.iitr.ac.in>
References: <20200819180442.11630-1-kgupta@es.iitr.ac.in>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Make separate functions for stopping streaming of entities in path of a
particular stream and stopping thread. This is needed to ensure that
thread doesn't stop when one device stops streaming in case of multiple
streams.

Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
---
 .../media/test-drivers/vimc/vimc-streamer.c   | 82 ++++++++++++-------
 1 file changed, 52 insertions(+), 30 deletions(-)

diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c b/drivers/media/test-drivers/vimc/vimc-streamer.c
index cc40ecabe95a..6b5ea1537952 100644
--- a/drivers/media/test-drivers/vimc/vimc-streamer.c
+++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
@@ -13,29 +13,59 @@
 #include "vimc-streamer.h"
 
 /**
- * vimc_streamer_pipeline_terminate - Disable stream in all ved in stream
+ * vimc_streamer_pipeline_terminate - Terminate the thread
  *
- * @stream: the pointer to the stream structure with the pipeline to be
- *	    disabled.
+ * @stream: the pointer to the stream structure
  *
- * Calls s_stream to disable the stream in each entity of the pipeline
+ * Erases values of stream struct and terminates the thread
  *
  */
 static void vimc_streamer_pipeline_terminate(struct vimc_stream *stream)
 {
 	struct vimc_ent_device *ved;
-	struct v4l2_subdev *sd;
 
 	while (stream->pipe_size) {
 		stream->pipe_size--;
 		ved = stream->ved_pipeline[stream->pipe_size];
 		stream->ved_pipeline[stream->pipe_size] = NULL;
+	}
 
-		if (!is_media_entity_v4l2_subdev(ved->ent))
-			continue;
+	kthread_stop(stream->kthread);
+	stream->kthread = NULL;
+}
 
-		sd = media_entity_to_v4l2_subdev(ved->ent);
-		v4l2_subdev_call(sd, video, s_stream, 0);
+/**
+ * vimc_streamer_stream_terminate - Disable stream in all ved in stream
+ *
+ * @ved: pointer to the ved for which stream needs to be disabled
+ *
+ * Calls s_stream to disable the stream in each entity of the stream
+ *
+ */
+static void vimc_streamer_stream_terminate(struct vimc_ent_device *ved)
+{
+	struct media_entity *entity = ved->ent;
+	struct video_device *vdev;
+	struct v4l2_subdev *sd;
+
+	while (entity) {
+		if (is_media_entity_v4l2_subdev(ved->ent)) {
+			sd = media_entity_to_v4l2_subdev(ved->ent);
+			v4l2_subdev_call(sd, video, s_stream, 0);
+		}
+		entity = vimc_get_source_entity(ved->ent);
+		if (!entity)
+			break;
+
+		if (is_media_entity_v4l2_subdev(entity)) {
+			sd = media_entity_to_v4l2_subdev(entity);
+			ved = v4l2_get_subdevdata(sd);
+		} else {
+			vdev = container_of(entity,
+					    struct video_device,
+					    entity);
+			ved = video_get_drvdata(vdev);
+		}
 	}
 }
 
@@ -43,25 +73,25 @@ static void vimc_streamer_pipeline_terminate(struct vimc_stream *stream)
  * vimc_streamer_stream_start - Starts streaming for all entities
  * in a stream
  *
- * @ved:    the pointer to the vimc entity initializing the stream
+ * @cved:    the pointer to the vimc entity initializing the stream
  *
  * Walks through the entity graph to call vimc_streamer_s_stream()
  * to enable stream in all entities in path of a stream.
  *
  * Return: 0 if success, error code otherwise.
  */
-static int vimc_streamer_stream_start(struct vimc_stream *stream,
-				      struct vimc_ent_device *ved)
+static int vimc_streamer_stream_start(struct vimc_ent_device *cved)
 {
 	struct media_entity *entity;
 	struct video_device *vdev;
 	struct v4l2_subdev *sd;
+	struct vimc_ent_device *ved = cved;
 	int stream_size = 0;
 	int ret = 0;
 
 	while (stream_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
 		if (!ved) {
-			vimc_streamer_pipeline_terminate(stream);
+			vimc_streamer_stream_terminate(cved);
 			return -EINVAL;
 		}
 
@@ -71,7 +101,7 @@ static int vimc_streamer_stream_start(struct vimc_stream *stream,
 			if (ret && ret != -ENOIOCTLCMD) {
 				dev_err(ved->dev, "subdev_call error %s\n",
 					ved->ent->name);
-				vimc_streamer_pipeline_terminate(stream);
+				vimc_streamer_stream_terminate(cved);
 				return ret;
 			}
 		}
@@ -84,7 +114,7 @@ static int vimc_streamer_stream_start(struct vimc_stream *stream,
 				dev_err(ved->dev,
 					"first entity in the pipe '%s' is not a source\n",
 					ved->ent->name);
-				vimc_streamer_pipeline_terminate(stream);
+				vimc_streamer_stream_terminate(cved);
 				pr_info ("first entry not source");
 				return -EPIPE;
 			}
@@ -104,7 +134,7 @@ static int vimc_streamer_stream_start(struct vimc_stream *stream,
 		stream_size++;
 	}
 
-	vimc_streamer_pipeline_terminate(stream);
+	vimc_streamer_stream_terminate(cved);
 	return -EINVAL;
 }
 
@@ -120,13 +150,14 @@ static int vimc_streamer_stream_start(struct vimc_stream *stream,
  * Return: 0 if success, error code otherwise.
  */
 static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
-				       struct vimc_ent_device *ved)
+				       struct vimc_ent_device *cved)
 {
 	struct media_entity *entity;
 	struct media_device *mdev;
 	struct media_graph graph;
 	struct video_device *vdev;
 	struct v4l2_subdev *sd;
+	struct vimc_ent_device *ved = cved;
 	int ret;
 
 	entity = ved->ent;
@@ -170,6 +201,7 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
 		}
 	}
 
+	vimc_streamer_stream_terminate(cved);
 	vimc_streamer_pipeline_terminate(stream);
 	return -EINVAL;
 }
@@ -246,7 +278,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
 		if (stream->kthread)
 			return 0;
 
-		ret = vimc_streamer_stream_start(stream, ved);
+		ret = vimc_streamer_stream_start(ved);
 		if (ret)
 			return ret;
 
@@ -260,6 +292,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
 		if (IS_ERR(stream->kthread)) {
 			ret = PTR_ERR(stream->kthread);
 			dev_err(ved->dev, "kthread_run failed with %d\n", ret);
+			vimc_streamer_stream_terminate(ved);
 			vimc_streamer_pipeline_terminate(stream);
 			stream->kthread = NULL;
 			return ret;
@@ -269,18 +302,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
 		if (!stream->kthread)
 			return 0;
 
-		ret = kthread_stop(stream->kthread);
-		/*
-		 * kthread_stop returns -EINTR in cases when streamon was
-		 * immediately followed by streamoff, and the thread didn't had
-		 * a chance to run. Ignore errors to stop the stream in the
-		 * pipeline.
-		 */
-		if (ret)
-			dev_dbg(ved->dev, "kthread_stop returned '%d'\n", ret);
-
-		stream->kthread = NULL;
-
+		vimc_streamer_stream_terminate(ved);
 		vimc_streamer_pipeline_terminate(stream);
 	}
 
-- 
2.17.1