As was discussed here (among other places): https://lkml.org/lkml/2018/10/19/440 using capture queue buffer indices to refer to reference frames is not a good idea. A better idea is to use a 'tag' (thanks to Alexandre for the excellent name; it's much better than 'cookie') where the application can assign a u64 tag to an output buffer, which is then copied to the capture buffer(s) derived from the output buffer. A u64 is chosen since this allows userspace to also use pointers to internal structures as 'tag'. The first two patches add core tag support, the next two patches add tag support to vim2m and vicodec, and the final patch (compile tested only!) adds support to the cedrus driver. I also removed the 'pad' fields from the mpeg2 control structs (it should never been added in the first place) and aligned the structs to a u32 boundary (u64 for the tag values). The cedrus code now also copies the timestamps (didn't happen before) but the sequence counter is still not set, that's something that should still be added. Note: if no buffer is found for a certain tag, then the dma address is just set to 0. That happened before as well with invalid buffer indices. This should be checked in the driver! Also missing in this series are documentation updates, which is why it is marked RFC. I would very much appreciate it if someone can test the cedrus driver with these changes. If it works, then I can prepare a real patch series for 4.20. It would be really good if the API is as stable as we can make it before 4.20 is released. Regards, Hans Changes since v1: - cookie -> tag - renamed v4l2_tag to v4l2_buffer_tag - dropped spurious 'to' in the commit log of patch 1 Hans Verkuil (5): videodev2.h: add tag support vb2: add tag support vim2m: add tag support vicodec: add tag support cedrus: add tag support .../media/common/videobuf2/videobuf2-v4l2.c | 43 ++++++++++++++++--- drivers/media/platform/vicodec/vicodec-core.c | 3 ++ drivers/media/platform/vim2m.c | 3 ++ drivers/media/v4l2-core/v4l2-ctrls.c | 9 ---- drivers/staging/media/sunxi/cedrus/cedrus.h | 8 ++-- .../staging/media/sunxi/cedrus/cedrus_dec.c | 10 +++++ .../staging/media/sunxi/cedrus/cedrus_mpeg2.c | 21 ++++----- include/media/videobuf2-v4l2.h | 18 ++++++++ include/uapi/linux/v4l2-controls.h | 14 +++--- include/uapi/linux/videodev2.h | 37 +++++++++++++++- 10 files changed, 127 insertions(+), 39 deletions(-) -- 2.19.1
