@@ -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);
@@ -386,6 +386,12 @@ struct vb2_buffer {
* the buffer contents will be ignored anyway.
* @buf_cleanup: called once before the buffer is freed; drivers may
* perform any additional cleanup; optional.
+ * @prepare_streaming: called once to prepare for 'streaming' state; this is
+ * where validation can be done to verify everything is
+ * okay and streaming resources can be claimed. It is
+ * called when the VIDIOC_STREAMON ioctl is called. The
+ * actual streaming starts when @start_streaming is called.
+ * Optional.
* @start_streaming: called once to enter 'streaming' state; the driver may
* receive buffers with @buf_queue callback
* before @start_streaming is called; the driver gets the
@@ -405,6 +411,10 @@ struct vb2_buffer {
* callback by calling vb2_buffer_done() with either
* %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
* vb2_wait_for_all_buffers() function
+ * @unprepare_streaming:called as counterpart to @prepare_streaming; any claimed
+ * streaming resources can be released here. It is
+ * called when the VIDIOC_STREAMOFF ioctls is called or
+ * when the streaming filehandle is closed. Optional.
* @buf_queue: passes buffer vb to the driver; driver may start
* hardware operation on this buffer; driver should give
* the buffer back by calling vb2_buffer_done() function;
@@ -432,8 +442,10 @@ struct vb2_ops {
void (*buf_finish)(struct vb2_buffer *vb);
void (*buf_cleanup)(struct vb2_buffer *vb);
+ int (*prepare_streaming)(struct vb2_queue *q);
int (*start_streaming)(struct vb2_queue *q, unsigned int count);
void (*stop_streaming)(struct vb2_queue *q);
+ void (*unprepare_streaming)(struct vb2_queue *q);
void (*buf_queue)(struct vb2_buffer *vb);
@@ -641,8 +653,10 @@ struct vb2_queue {
u32 cnt_queue_setup;
u32 cnt_wait_prepare;
u32 cnt_wait_finish;
+ u32 cnt_prepare_streaming;
u32 cnt_start_streaming;
u32 cnt_stop_streaming;
+ u32 cnt_unprepare_streaming;
#endif
};
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 <hverkuil-cisco@xs4all.nl> --- .../media/common/videobuf2/videobuf2-core.c | 25 ++++++++++++++++--- include/media/videobuf2-core.h | 14 +++++++++++ 2 files changed, 35 insertions(+), 4 deletions(-)