[media] media: vb2: change queue initialization order
This patch changes the order of operations during stream on call. Now the
buffers are first queued to the driver and then the start_streaming method
is called.
This resolves the most common case when the driver needs to know buffer
addresses to enable dma engine and start streaming. Additional parameter
to start_streaming method have been added to simplify drivers code. The
driver are now obliged to check if the number of queued buffers is high
enough to enable hardware streaming. If not - it can return an error. In
such case all the buffers that have been pre-queued are invalidated.
This patch also updates all videobuf2 clients to work properly with the
changed order of operations.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
CC: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
CC: Hans Verkuil <hverkuil@xs4all.nl>
CC: Tomasz Stanislawski <t.stanislaws@samsung.com>
CC: Sylwester Nawrocki <s.nawrocki@samsung.com>
CC: Kamil Debski <k.debski@samsung.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Josh Wu <josh.wu@atmel.com>
CC: Hans de Goede <hdegoede@redhat.com>
CC: Paul Mundt <lethal@linux-sh.org>
Tested-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index e89fd53..6687ac3 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -1111,73 +1111,6 @@
EXPORT_SYMBOL_GPL(vb2_dqbuf);
/**
- * vb2_streamon - start streaming
- * @q: videobuf2 queue
- * @type: type argument passed from userspace to vidioc_streamon handler
- *
- * Should be called from vidioc_streamon handler of a driver.
- * This function:
- * 1) verifies current state
- * 2) starts streaming and passes any previously queued buffers to the driver
- *
- * The return values from this function are intended to be directly returned
- * from vidioc_streamon handler in the driver.
- */
-int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
-{
- struct vb2_buffer *vb;
- int ret;
-
- if (q->fileio) {
- dprintk(1, "streamon: file io in progress\n");
- return -EBUSY;
- }
-
- if (type != q->type) {
- dprintk(1, "streamon: invalid stream type\n");
- return -EINVAL;
- }
-
- if (q->streaming) {
- dprintk(1, "streamon: already streaming\n");
- return -EBUSY;
- }
-
- /*
- * Cannot start streaming on an OUTPUT device if no buffers have
- * been queued yet.
- */
- if (V4L2_TYPE_IS_OUTPUT(q->type)) {
- if (list_empty(&q->queued_list)) {
- dprintk(1, "streamon: no output buffers queued\n");
- return -EINVAL;
- }
- }
-
- /*
- * Let driver notice that streaming state has been enabled.
- */
- ret = call_qop(q, start_streaming, q);
- if (ret) {
- dprintk(1, "streamon: driver refused to start streaming\n");
- return ret;
- }
-
- q->streaming = 1;
-
- /*
- * If any buffers were queued before streamon,
- * we can now pass them to driver for processing.
- */
- list_for_each_entry(vb, &q->queued_list, queued_entry)
- __enqueue_in_driver(vb);
-
- dprintk(3, "Streamon successful\n");
- return 0;
-}
-EXPORT_SYMBOL_GPL(vb2_streamon);
-
-/**
* __vb2_queue_cancel() - cancel and stop (pause) streaming
*
* Removes all queued buffers from driver's queue and all buffers queued by
@@ -1215,6 +1148,64 @@
}
/**
+ * vb2_streamon - start streaming
+ * @q: videobuf2 queue
+ * @type: type argument passed from userspace to vidioc_streamon handler
+ *
+ * Should be called from vidioc_streamon handler of a driver.
+ * This function:
+ * 1) verifies current state
+ * 2) passes any previously queued buffers to the driver and starts streaming
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_streamon handler in the driver.
+ */
+int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
+{
+ struct vb2_buffer *vb;
+ int ret;
+
+ if (q->fileio) {
+ dprintk(1, "streamon: file io in progress\n");
+ return -EBUSY;
+ }
+
+ if (type != q->type) {
+ dprintk(1, "streamon: invalid stream type\n");
+ return -EINVAL;
+ }
+
+ if (q->streaming) {
+ dprintk(1, "streamon: already streaming\n");
+ return -EBUSY;
+ }
+
+ /*
+ * If any buffers were queued before streamon,
+ * we can now pass them to driver for processing.
+ */
+ list_for_each_entry(vb, &q->queued_list, queued_entry)
+ __enqueue_in_driver(vb);
+
+ /*
+ * Let driver notice that streaming state has been enabled.
+ */
+ ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
+ if (ret) {
+ dprintk(1, "streamon: driver refused to start streaming\n");
+ __vb2_queue_cancel(q);
+ return ret;
+ }
+
+ q->streaming = 1;
+
+ dprintk(3, "Streamon successful\n");
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_streamon);
+
+
+/**
* vb2_streamoff - stop streaming
* @q: videobuf2 queue
* @type: type argument passed from userspace to vidioc_streamoff handler