From e4e70a147a48618a36ae1b81c641516cb9d45993 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Fri, 8 Jul 2016 06:20:51 -0300 Subject: [PATCH] [media] v4l: vsp1: Prevent pipelines from running when not streaming Pipelines can only be run if all their video nodes are streaming. Commit b4dfb9b35a19 ("[media] v4l: vsp1: Stop the pipeline upon the first STREAMOFF") fixed the pipeline stop sequence, but introduced a race condition that makes it possible to run a pipeline after stopping the stream on a video node by queuing a buffer on the other side of the pipeline. Fix this by clearing the buffers ready flag when stopping the stream, which will prevent the QBUF handler from running the pipeline. Fixes: b4dfb9b35a19 ("[media] v4l: vsp1: Stop the pipeline upon the first STREAMOFF") Reported-by: Kieran Bingham Tested-by: Kieran Bingham Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/vsp1/vsp1_video.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/media/platform/vsp1/vsp1_video.c b/drivers/media/platform/vsp1/vsp1_video.c index 9fb4fc2..ed9759e 100644 --- a/drivers/media/platform/vsp1/vsp1_video.c +++ b/drivers/media/platform/vsp1/vsp1_video.c @@ -675,6 +675,13 @@ static void vsp1_video_stop_streaming(struct vb2_queue *vq) unsigned long flags; int ret; + /* Clear the buffers ready flag to make sure the device won't be started + * by a QBUF on the video node on the other side of the pipeline. + */ + spin_lock_irqsave(&video->irqlock, flags); + pipe->buffers_ready &= ~(1 << video->pipe_index); + spin_unlock_irqrestore(&video->irqlock, flags); + mutex_lock(&pipe->lock); if (--pipe->stream_count == pipe->num_inputs) { /* Stop the pipeline. */ -- 2.7.4