Add support for two new (un)prepare_streaming queue ops that are called
when the user calls VIDIOC_STREAMON and STREAMOFF (or closes the fh).
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
This has only been compile tested. Eugen, can you try this with the
atmel-isc series?
The kerneldoc documentation in core.h can be better, but that's why this
is an RFC :-)
Changes since v1: fixed 'unbalanced' assignment in __vb2_queue_free,
replacing a ';' with '||'.
---
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index b203c1e26353..7fd38fc4b9e2 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 +2110,10 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
return -EINVAL;
}
+ ret = call_qop(q, prepare_streaming, q);
+ if (ret)
+ return ret;
+
/*
* Tell driver to start streaming provided sufficient buffers
* are available.
@@ -2109,16 +2121,20 @@ 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);
+ return ret;
}
EXPORT_SYMBOL_GPL(vb2_core_streamon);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 5468b633b9d2..623146476157 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -386,6 +386,9 @@ 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 to start streaming later. 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 +408,7 @@ 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. 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 +436,10 @@ 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 +647,10 @@ 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
};
