From a10b215325740376ed551814a37d1f8e9d6b1ced Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Wed, 22 Jun 2022 10:31:44 +0100 Subject: media: vb2: add (un)prepare_streaming queue ops When userspace called VIDIOC_STREAMON, then you want to claim any streaming resources needed and validate the video pipeline. Waiting for start_streaming to be called is too late, since that can be postponed until the required minimum of buffers is queued. So add a prepare_streaming op (optional) that can be used for that purpose, and a matching unprepare_streaming op (optional) that can release any claimed resources. The unprepare_streaming op is called when VIDIOC_STREAMOFF is called and q->streaming is 1, or when the filehandle is closed while q->streaming is 1. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/common/videobuf2/videobuf2-core.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'drivers/media/common') diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index ab9697f3b5f1..17e2463c054c 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -544,6 +544,7 @@ static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers) */ if (q->num_buffers) { bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming || + q->cnt_prepare_streaming != q->cnt_unprepare_streaming || q->cnt_wait_prepare != q->cnt_wait_finish; if (unbalanced || debug) { @@ -552,14 +553,18 @@ static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers) pr_info(" setup: %u start_streaming: %u stop_streaming: %u\n", q->cnt_queue_setup, q->cnt_start_streaming, q->cnt_stop_streaming); + pr_info(" prepare_streaming: %u unprepare_streaming: %u\n", + q->cnt_prepare_streaming, q->cnt_unprepare_streaming); pr_info(" wait_prepare: %u wait_finish: %u\n", q->cnt_wait_prepare, q->cnt_wait_finish); } q->cnt_queue_setup = 0; q->cnt_wait_prepare = 0; q->cnt_wait_finish = 0; + q->cnt_prepare_streaming = 0; q->cnt_start_streaming = 0; q->cnt_stop_streaming = 0; + q->cnt_unprepare_streaming = 0; } for (buffer = 0; buffer < q->num_buffers; ++buffer) { struct vb2_buffer *vb = q->bufs[buffer]; @@ -1991,6 +1996,9 @@ static void __vb2_queue_cancel(struct vb2_queue *q) if (q->start_streaming_called) call_void_qop(q, stop_streaming, q); + if (q->streaming) + call_void_qop(q, unprepare_streaming, q); + /* * If you see this warning, then the driver isn't cleaning up properly * in stop_streaming(). See the stop_streaming() documentation in @@ -2102,6 +2110,12 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type) return -EINVAL; } + ret = call_qop(q, prepare_streaming, q); + if (ret) + return ret; + + q->streaming = 1; + /* * Tell driver to start streaming provided sufficient buffers * are available. @@ -2109,16 +2123,19 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type) if (q->queued_count >= q->min_buffers_needed) { ret = v4l_vb2q_enable_media_source(q); if (ret) - return ret; + goto unprepare; ret = vb2_start_streaming(q); if (ret) - return ret; + goto unprepare; } - q->streaming = 1; - dprintk(q, 3, "successful\n"); return 0; + +unprepare: + call_void_qop(q, unprepare_streaming, q); + q->streaming = 0; + return ret; } EXPORT_SYMBOL_GPL(vb2_core_streamon); -- cgit v1.2.3