Re: [RFC PATCH v2] media: renesas: vsp1: Add VSPD underrun detection & tracing

[Eugeniu Rosca <erosca@de.adit-jv.com>]

Dear Laurent,
Dear Kieran,
Dear community,

On Di, Mai 03, 2022 at 03:20:10 +0200, Eugeniu Rosca wrote:
> A barely noticeable (especially if hardly reproducible) display flicker
> may not be the biggest concern in the development environment. However,
> an automotive OEM will not only notice it, but will also be haunted by
> its phenomenon/nature till it is understood in the greatest detail and
> ultimately eradicated, to avoid impairing user experience.
> 
> Troubleshooting the above without the right tools becomes a nightmare.
> 
> Since VSPD underruns may indeed cause [1] display flicker, we believe
> that having a minimal/lightweight support for detecting and logging
> such events would be extremely beneficial. Obviously, this only applies
> to VSP2 modules having an interface to DU (i.e. not mem2mem).
> 
> This implementation is heavily inspired by Koji Matsuoka's work [2-3],
> but has been refactored to hopefully become production/mainline-friendly
> (the original feature is intended for the development environment only).
> 
> [1] https://lore.kernel.org/linux-renesas-soc/20220421161259.GA2660@lxhi-065
> [2] https://github.com/renesas-rcar/linux-bsp/commit/3469001c3098
>     ("v4l: vsp1: Add underrun hung-up workaround")
> [3] https://github.com/renesas-rcar/linux-bsp/commit/12ea79975a10
>     ("v4l: vsp1: Add underrun debug messege option")
> 
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Kieran Bingham <kieran.bingham@ideasonboard.com>
> Cc: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
> ---

I apologize for another friendly reminder, but is there any chance
to get a bit of attention from your side regarding this patch,
which is intended to make our life easier in production?

I hope the RFC tag does not convey the lack of confidence, importance
and/or time spent for implementation and testing on our side.

This v2 version fixed all review comments and issues which popped up
during internal testing, so I am very hopeful and looking forward to
your precious feedback.

We have also made aware Renesas Japan that this patch is important to
us, hoping that potentially there is another communication bridge
between them and Renesas OSS community.

Best regards,
Eugeniu Rosca