Re: [PATCH v4 0/7] media: mediatek: vcodec: fix v4l2_ctrl_request_complete fail

[Nicolas Dufresne <nicolas.dufresne@collabora.com>]

Hi Yunfei,

Le mercredi 07 août 2024 à 16:24 +0800, Yunfei Dong a écrit :
> v4l2_m2m_buf_done is called in lat work queue, v4l2_ctrl_request_complete
> is called in core queue. The request status of output queue will be set to
> MEDIA_REQUEST_STATE_COMPLETE when v4l2_m2m_buf_done is called, leading to
> output queue request complete fail. Must move v4l2_ctrl_request_complete
> in front of v4l2_m2m_buf_done.

Sebastian and I have analyzed further the issue and the description here does
not seem to match. What happens is that in Stateless decoding, you have to set
header controls out-of-request to negotiate the format at first.

With VP9 notably, the header control is the only control there is. Chromium will
optimize out this and only attach a bitstream buffer to the request. So when the
buffer is mark to done, it is the last object in the request, which implicitly
mark the request as complete.

When v4l2_ctrl_request_complete() is later called, the control code detect that
there is no controls in the request. It then creates an empty control, but
attaching an object to a completed request is not allowed.

> 
> Patch 1 setting request complete before buffer done
> Patch 2 change flush decode order when stream off
> Patch 3 flush decoder before stream off
> Patch 4 using input information to get vb2 buffer
> Patch 5 store source vb2 buffer
> Patch 6 replace v4l2_m2m_next_src_buf with v4l2_m2m_src_buf_remove
> Patch 7 remove media request checking

I will give a some testing soon. Can you clarify on if the LAT and the CORE
still runs in parallel after this change ?

Nicolas

> 
> ---
> compared with v3:
> - fix flush decoder issue when userspace stream off capture queue firstly
> - fluster test result same with v3
> 
> compared with v2:
> - add patch 5/6/7 to fix decode again issue
> - add fluster test result with mt8195 platform(same with no changed):
>   1> ./fluster.py run -d GStreamer-VP8-V4L2SL-Gst1.0 -j1 -t 90
>      VP8-TEST-VECTORS 59/61
>   2> ./fluster.py run -d GStreamer-VP9-V4L2SL-Gst1.0 -j1 -t 90
>      VP9-TEST-VECTORS 276/305
>   3> ./fluster.py run -d GStreamer-AV1-V4L2SL-Gst1.0 -j1 -t 90
>      AV1-TEST-VECTORS 237/239
>   4> ./fluster.py run -d GStreamer-H.264-V4L2SL-Gst1.0 -j1 -t 90
>      JVT-AVC_V1       95/135
>   5> ./fluster.py run -d GStreamer-H.265-V4L2SL-Gst1.0 -j1 -t 90
>      JCT-VC-HEVC_V1   142/147
> 
> compared with v1:
> - add patch 2/3/4 to fix timing issue.
> ---
> Yunfei Dong (7):
>   media: mediatek: vcodec: setting request complete before buffer done
>   media: mediatek: vcodec: change flush decode order when stream off
>   media: mediatek: vcodec: flush decoder before stream off
>   media: mediatek: vcodec: using input information to get vb2 buffer
>   media: mediatek: vcodec: store source vb2 buffer
>   media: mediatek: vcodec: replace v4l2_m2m_next_src_buf with
>     v4l2_m2m_src_buf_remove
>   media: mediatek: vcodec: remove media request checking
> 
>  .../mediatek/vcodec/decoder/mtk_vcodec_dec.c  | 44 ++++++++---------
>  .../vcodec/decoder/mtk_vcodec_dec_drv.h       |  4 +-
>  .../vcodec/decoder/mtk_vcodec_dec_stateless.c | 48 ++++++++++++++-----
>  .../vcodec/decoder/vdec/vdec_av1_req_lat_if.c | 18 +++----
>  .../decoder/vdec/vdec_h264_req_multi_if.c     |  4 +-
>  .../decoder/vdec/vdec_hevc_req_multi_if.c     |  4 +-
>  .../vcodec/decoder/vdec/vdec_vp9_req_lat_if.c | 19 ++++----
>  .../mediatek/vcodec/decoder/vdec_msg_queue.h  |  4 +-
>  8 files changed, 85 insertions(+), 60 deletions(-)
>