Re: [PATCH 0/9] media: rkvdec: Add HEVC backend

[Jonas Karlman]

Hi Hans,

On 2023-11-07 14:49, Hans Verkuil wrote:
> Hi Jonas,
> 
> On 06/11/2023 00:36, Jonas Karlman wrote:
>> This series add a HEVC backend to the Rockchip Video Decoder driver.
>>
>> A version of this HEVC backend has been in use by the LibreELEC distro
>> for the past 3+ years [1]. It was initially created based on a copy of
>> the H264 backend, unstable HEVC uAPI controls and a cabac table + scaling
>> matrix functions shamelessly copied 1:1 from the Rockchip mpp library.
>>
>> It has since then been extended to use the stable HEVC uAPI controls and
>> improved opon e.g. to include support for rk3288 and fix decoding issues
>> by Alex Bee and Nicolas Dufresne.
>>
>> The version submitted in this series is based on the code currently used
>> by the LibreELEC distro, excluding hard/soft reset, and with cabac table
>> and scaling matrix functions picked from Sebastian Fricke prior series
>> to add a HEVC backend [2].
>>
>> Big thanks to Alex Bee, Nicolas Dufresne and Sebastian Fricke for making
>> this series possible!
> 
> I ran this series through smatch and found these two issues:
> 
> drivers/staging/media/rkvdec/rkvdec-hevc.c: In function 'transpose_and_flatten_matrices':
> drivers/staging/media/rkvdec/rkvdec-hevc.c:429:83: warning: variable 'new_value' set but not used [-Wunused-but-set-variable]
>   429 |         int i, j, row, x_offset, matrix_offset, rot_index, y_offset, matrix_size, new_value;
>       |                                                                                   ^~~~~~~~~
> drivers/staging/media/rkvdec/rkvdec-hevc.c:756 rkvdec_hevc_run_preamble() error: we previously assumed 'ctrl' could be null (see line 755)

Thanks, will fix in v2.

> 
> Also, this series drops the HEVC part from the TODO file, but
> I wonder if the last remaining item is still valid:
> 
> * Evaluate introducing a helper to consolidate duplicated
>   code in rkvdec_request_validate and cedrus_request_validate.
>   The helper needs to the driver private data associated with
>   the videobuf2 queue, from a media request.
> 
> It doesn't look like there is much duplicate code at all. It is certainly not
> something that prevents this driver from moving out of staging.

I agree, if this is still valid it is not something that should prevent
this driver from moving out of staging.

There is however one remaining feature/issue that is not listed in TODO.

In certain situations the hw block may need a reset after there has been
a decoding error, especially after a hevc decoding error. Decoding can
typically be re-started with successful result after a short pm
autosuspend timeout.

We do have a soft/hard reset implementation in LibreELEC-distro,
excluded it from this series because reset is typically not needed, and
I think the reset code need some rework to be upstream ready.

Would missing hard reset support be a reason for keeping this driver
in staging?

Regards,
Jonas

> 
> Regards,
> 
> 	Hans
> 
>>
>> Patch 1 add the new HEVC backend.
>> Patch 2-3 add variants support to the driver.
>> Patch 4 add support for a rk3288 variant.
>> Patch 5 add a rk3328 variant to work around hw quirks.
>> Patch 6-7 add device tree node for rk3288.
>> Patch 8-9 extend vdec node reg size to include cache/perf registers.
>>
>> This was tested on a ROCK Pi 4 (RK3399) and Rock64 (RK3328):
>>
>>   v4l2-compliance 1.24.1, 64 bits, 64-bit time_t
>>   ...
>>   Total for rkvdec device /dev/video1: 46, Succeeded: 46, Failed: 0, Warnings: 0
>>
>>   Running test suite JCT-VC-HEVC_V1 with decoder FFmpeg-H.265-V4L2-request
>>   ...
>>   Ran 135/147 tests successfully
>>
>>   Running test suite JCT-VC-MV-HEVC with decoder FFmpeg-H.265-V4L2-request
>>   ...
>>   Ran 9/9 tests successfully
>>
>> And on a TinkerBoard (RK3288):
>>
>>   v4l2-compliance 1.24.1, 32 bits, 32-bit time_t
>>   ...
>>   Total for rkvdec device /dev/video3: 47, Succeeded: 47, Failed: 0, Warnings: 0
>>
>>   Running test suite JCT-VC-HEVC_V1 with decoder FFmpeg-H.265-V4L2-request
>>   ...
>>   Ran 137/147 tests successfully
>>
>>   Running test suite JCT-VC-MV-HEVC with decoder FFmpeg-H.265-V4L2-request
>>   ...
>>   Ran 9/9 tests successfully
>>
>> This series depend on the following series:
>> - media: rkvdec: Add H.264 High 10 and 4:2:2 profile support [3]
>>
>> To fully runtime test this series you need above series and ffmpeg
>> patches from [4], this series and its depends is also available at [5].
>>
>> Full summary of fluster run can be found at [6].
>>
>> [1] https://github.com/LibreELEC/LibreELEC.tv/blob/master/projects/Rockchip/patches/linux/default/linux-2000-v4l2-wip-rkvdec-hevc.patch
>> [2] https://lore.kernel.org/linux-media/20230101-patch-series-v2-6-2-rc1-v2-0-fa1897efac14@xxxxxxxxxxxxx/
>> [3] https://lore.kernel.org/linux-media/20231105165521.3592037-1-jonas@xxxxxxxxx/
>> [4] https://github.com/Kwiboo/FFmpeg/commits/v4l2-request-n6.1-dev/
>> [5] https://github.com/Kwiboo/linux-rockchip/commits/linuxtv-rkvdec-hevc-v1/
>> [6] https://gist.github.com/Kwiboo/4c0ed87774dede44ce6838451a1ec93d
>>
>> Regards,
>> Jonas
>>
>> Alex Bee (5):
>>   media: rkvdec: Add variants support
>>   media: rkvdec: Add RK3288 variant
>>   media: rkvdec: Disable QoS for HEVC and VP9 on RK3328
>>   ARM: dts: rockchip: Add vdec node for RK3288
>>   arm64: dts: rockchip: Expand reg size of vdec node for RK3399
>>
>> Jonas Karlman (4):
>>   media: rkvdec: Add HEVC backend
>>   media: rkvdec: Implement capability filtering
>>   media: dt-bindings: rockchip,vdec: Add RK3288 compatible
>>   arm64: dts: rockchip: Expand reg size of vdec node for RK3328
>>
>>  .../bindings/media/rockchip,vdec.yaml         |    4 +-
>>  arch/arm/boot/dts/rockchip/rk3288.dtsi        |   17 +-
>>  arch/arm64/boot/dts/rockchip/rk3328.dtsi      |    2 +-
>>  arch/arm64/boot/dts/rockchip/rk3399.dtsi      |    6 +-
>>  drivers/staging/media/rkvdec/Makefile         |    2 +-
>>  drivers/staging/media/rkvdec/TODO             |    7 -
>>  .../staging/media/rkvdec/rkvdec-hevc-data.c   | 1848 +++++++++++++++++
>>  drivers/staging/media/rkvdec/rkvdec-hevc.c    |  823 ++++++++
>>  drivers/staging/media/rkvdec/rkvdec-regs.h    |    3 +
>>  drivers/staging/media/rkvdec/rkvdec-vp9.c     |   10 +
>>  drivers/staging/media/rkvdec/rkvdec.c         |  180 +-
>>  drivers/staging/media/rkvdec/rkvdec.h         |   15 +
>>  12 files changed, 2886 insertions(+), 31 deletions(-)
>>  create mode 100644 drivers/staging/media/rkvdec/rkvdec-hevc-data.c
>>  create mode 100644 drivers/staging/media/rkvdec/rkvdec-hevc.c
>>
>