On Tue, Jul 28, 2020 at 04:00:46PM +0200, Dafna Hirschfeld wrote: > > > On 28.07.20 14:07, Dafna Hirschfeld wrote: > > Hi > > > > On 28.07.20 13:39, Kaaira Gupta wrote: > > > On Mon, Jul 27, 2020 at 02:54:30PM -0300, Helen Koike wrote: > > > > Hi, > > > > > > > > On 7/27/20 11:31 AM, Kieran Bingham wrote: > > > > > Hi all, > > > > > > > > > > +Dafna for the thread discussion, as she's missed from the to/cc list. > > > > > > > > > > > > > > > On 24/07/2020 13:21, Kaaira Gupta wrote: > > > > > > On Fri, Jul 24, 2020 at 02:15:21PM +0200, Niklas Söderlund wrote: > > > > > > Hi, > > > > > > > > > > > > > Hi Kaaira, > > > > > > > > > > > > > > Thanks for your work. > > > > > > > > > > > > Thanks for yours :D > > > > > > > > > > > > > > > > > > > > On 2020-07-24 17:32:10 +0530, Kaaira Gupta wrote: > > > > > > > > This is version 2 of the patch series posted by Niklas for allowing > > > > > > > > multiple streams in VIMC. > > > > > > > > The original series can be found here: > > > > > > > > https://patchwork.kernel.org/cover/10948831/ > > > > > > > > > > > > > > > > This series adds support for two (or more) capture devices to be > > > > > > > > connected to the same sensors and run simultaneously. Each capture device > > > > > > > > can be started and stopped independent of each other. > > > > > > > > > > > > > > > > Patch 1/3 and 2/3 deals with solving the issues that arises once two > > > > > > > > capture devices can be part of the same pipeline. While 3/3 allows for > > > > > > > > two capture devices to be part of the same pipeline and thus allows for > > > > > > > > simultaneously use. > > > > I wonder if these two patches are enough, since each vimc entity also have > > a 'process_frame' callback, but only one allocated frame. That means > > that the 'process_frame' can be called concurrently by two different streams > > on the same frame and cause corruption. > > > > I think we should somehow change the vimc-stream.c code so that we have only > one stream process per pipe. So if one capture is already streaming, then the new > capture that wants to stream uses the same thread so we don't have two threads > both calling 'process_frame'. I didn't understand this well, can you please elaborate? How will it lead to the new capture using same thread? > > The second capture that wants to stream should iterate the topology downwards until > reaching an entity that already belong to the stream path of the other streaming capture > and tell the streamer it wants to read the frames this entity > produces. The first version of this series was doing this itself I think. But it was for connecting the pipe(capture) at the sensor if one already exists. > > Thanks, > Dafna > > > Thanks, > > Dafna > > > > > > > > > > > > > > > > I'm just curious if you are aware of this series? It would replace the > > > > > > > need for 1/3 and 2/3 of this series right? > > > > > > > > > > > > v3 of this series replaces the need for 1/3, but not the current version > > > > > > (ie v4). v4 of patch 2/5 removes the stream_counter that is needed to > > > > > > keep count of the calls to s_stream. Hence 1/3 becomes relevant again. > > > > > > > > > > So the question really is, how do we best make use of the two current > > > > > series, to achieve our goal of supporting multiple streams. > > > > > > > > > > Having not parsed Dafna's series yet, do we need to combine elements of > > > > > both ? Or should we work towards starting with this series and get > > > > > dafna's patches built on top ? > > > > > > > > > > Or should patch 1/3 and 3/3 of this series be on top of Dafna's v4 ? > > > > > > > > > > (It might be noteworthy to say that Kaaira has reported successful > > > > > multiple stream operation from /this/ series and her development branch > > > > > on libcamera). > > > > > > > > Dafna's patch seems still under discussion, but I don't want to block progress in Vimc either. > > > > > > > > So I was wondering if we can move forward with Vimc support for multistreaming, > > > > without considering Dafna's patchset, and we can do the clean up later once we solve that. > > > > > > > > What do you think? > > > > > > I agree with supporting multiple streams with VIMC with this patchset, > > > and then we can refactor the counters for s_stream in VIMC later (over > > > this series) if dafna includes them in subsequent version of her patchset. > > > > > > > I also think that adding support in the code will take much longer and should not > > stop us from supporting vimc independently. > > > > Thanks, > > Dafna > > > > > > > > > > Regards, > > > > Helen > > > > > > > > > > > > > > > > > > > > > 1. https://lore.kernel.org/linux-media/20200522075522.6190-1-dafna.hirschfeld@xxxxxxxxxxxxx/ > > > > > > > > > > > > > > > > > > > > > > > Changes since v1: > > > > > > > > - All three patches rebased on latest media-tree. > > > > > > > > Patch 3: > > > > > > > > - Search for an entity with a non-NULL pipe instead of searching > > > > > > > > for sensor. This terminates the search at output itself. > > > > > > > > > > > > > > > > Kaaira Gupta (3): > > > > > > > > media: vimc: Add usage count to subdevices > > > > > > > > media: vimc: Serialize vimc_streamer_s_stream() > > > > > > > > media: vimc: Join pipeline if one already exists > > > > > > > > > > > > > > > > .../media/test-drivers/vimc/vimc-capture.c | 35 ++++++++++++++++++- > > > > > > > > .../media/test-drivers/vimc/vimc-debayer.c | 8 +++++ > > > > > > > > drivers/media/test-drivers/vimc/vimc-scaler.c | 8 +++++ > > > > > > > > drivers/media/test-drivers/vimc/vimc-sensor.c | 9 ++++- > > > > > > > > .../media/test-drivers/vimc/vimc-streamer.c | 23 +++++++----- > > > > > > > > 5 files changed, 73 insertions(+), 10 deletions(-) > > > > > > > > > > > > > > > > -- > > > > > > > > 2.17.1 > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > Regards, > > > > > > > Niklas Söderlund > > > > >
