diff mbox series

[v3,6/9] media: vimc: Serialize vimc_streamer_s_stream()

Message ID 20200819180442.11630-7-kgupta@es.iitr.ac.in
State New
Headers show
Series [v3,1/9] media: vimc: Move get_source_entity to vimc-common | expand

Commit Message

Kaaira Gupta Aug. 19, 2020, 6:04 p.m. UTC 
From: Niklas Söderlund <niklas.soderlund@ragnatech.se>

Prepare for multiple video streams from the same sensor by serializing
vimc_streamer_s_stream(). Multiple streams will allow for multiple
concurrent calls to this function that could involve the same
subdevices.

If that happens the internal state of the involved subdevices could go
out of sync as they are being started and stopped at the same time,
prevent this by serializing starting and stopping of the vimc streamer.

[Kaaira: only rebased the patch on current HEAD of media-tree]

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
---
 .../media/test-drivers/vimc/vimc-streamer.c    | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c b/drivers/media/test-drivers/vimc/vimc-streamer.c
index 6b5ea1537952..f5c9e2f3bbcb 100644
--- a/drivers/media/test-drivers/vimc/vimc-streamer.c
+++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
@@ -269,22 +269,27 @@  int vimc_streamer_s_stream(struct vimc_stream *stream,
 			   struct vimc_ent_device *ved,
 			   int enable)
 {
+	static DEFINE_MUTEX(vimc_streamer_lock);
 	int ret;
 
 	if (!stream || !ved)
 		return -EINVAL;
 
+	ret = mutex_lock_interruptible(&vimc_streamer_lock);
+	if (ret)
+		return ret;
+
 	if (enable) {
 		if (stream->kthread)
 			return 0;
 
 		ret = vimc_streamer_stream_start(ved);
 		if (ret)
-			return ret;
+			goto out;
 
 		ret = vimc_streamer_pipeline_init(stream, ved);
 		if (ret)
-			return ret;
+			goto out;
 
 		stream->kthread = kthread_run(vimc_streamer_thread, stream,
 					      "vimc-streamer thread");
@@ -294,17 +299,16 @@  int vimc_streamer_s_stream(struct vimc_stream *stream,
 			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;
 		}
 
 	} else {
 		if (!stream->kthread)
-			return 0;
+			goto out;
 
 		vimc_streamer_stream_terminate(ved);
 		vimc_streamer_pipeline_terminate(stream);
 	}
-
-	return 0;
+out:
+	mutex_unlock(&vimc_streamer_lock);
+	return ret;
 }