Re: [PATCH v7 0/8] Cedrus driver for the Allwinner Video Engine, using media requests

From: Ezequiel Garcia
Date: Wed Aug 22 2018 - 13:25:15 EST


Hey Paul,

On Thu, 2018-08-09 at 11:04 +0200, Paul Kocialkowski wrote:
> This is the seventh iteration of the updated Cedrus driver,
> that supports the Video Engine found on most Allwinner SoCs, starting
> with the A10. It was tested on the A13, A20, A33 and H3.
>
> The initial version of this driver[0] was originally written and
> submitted by Florent Revest using a previous version of the request API
> that is necessary to provide coherency between controls and the buffers
> they apply to.
>
> The driver was adapted to use the latest version of the media request
> API[1], as submitted by Hans Verkuil. Media request API support is a
> hard requirement for the Cedrus driver.
>
> The driver itself currently only supports MPEG2 and more codecs will be
> added eventually. The default output frame format provided by the Video
> Engine is a multi-planar tiled YUV format (based on NV12). A specific
> format is introduced in the V4L2 API to describe it. Starting with the
> A33, the Video Engine can also output untiled YUV formats.
>
> This implementation is based on the significant work that was conducted
> by various members of the linux-sunxi community for understanding and
> documenting the Video Engine's innards.
>
> In addition to the media requests API, the following series are required
> for Cedrus:
> * vicodec: the Virtual Codec driver
> * allwinner: a64: add SRAM controller / system control
> * SRAM patches from the Cedrus VPU driver series version 5
>
> Changes since v6:
> * Reworked MPEG2 controls to stick closer to the bitstream;
> * Updated controls documentation accordingly and added requested fixes;
> * Renamed tiled format to V4L2_PIX_FMT_SUNXI_TILED_NV12;
> * Added various minor driver fixes based on Hans' feedback;
> * Fixed dst frame alignment based on Jernej's feedback and tests;
> * Removed set bits for the disabled secondary output.
>
> Changes since v5:
> * Added MPEG2 quantization matrices definitions and support;
> * Cleaned up registers definitions;
> * Moved the driver to staging as requested;
>

I tried to find the reason for moving this driver to staging,
but couldn't find it in the discussion.

If there's a legitimate reason, shouldn't you add a TODO file?

Thanks,
Eze