[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 <[email protected]>
Signed-off-by: Kyungmin Park <[email protected]>
CC: Pawel Osciak <[email protected]>
CC: Guennadi Liakhovetski <[email protected]>
CC: Hans Verkuil <[email protected]>
CC: Tomasz Stanislawski <[email protected]>
CC: Sylwester Nawrocki <[email protected]>
CC: Kamil Debski <[email protected]>
CC: Jonathan Corbet <[email protected]>
CC: Josh Wu <[email protected]>
CC: Hans de Goede <[email protected]>
CC: Paul Mundt <[email protected]>
Tested-by: Josh Wu <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

0 files changed, 0 insertions, 0 deletions