On Mon, 29 Aug 2011, Marek Szyprowski wrote: > Hello, > > On Monday, August 29, 2011 2:05 PM Guennadi Liakhovetski wrote: > > > Hi Marek > > > > On Mon, 29 Aug 2011, Marek Szyprowski wrote: > > > > > 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]> > > > --- > > > > > > Hello, > > > > > > This is yet another version of the patch that introduces significant > > > changes in the vb2 streamon operation. I've decided to remove the > > > additional parameter to buf_queue callback and added a few cleanups here > > > and there. This patch also includes an update for all vb2 clients. > > > > Just for the record: These are not all vb2 clients. A simple grep for > > something like vb2_ops gives you also > > > > drivers/media/video/mx3_camera.c > > drivers/media/video/sh_mobile_ceu_camera.c > > Yes, they are also vb2 clients, but since they don't use start_streaming() > callback no changes were needed there. Same applies to mem2mem_testdev driver.
Great, thanks for the explanation! Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
