Re: [PATCH v9 00/28] Qualcomm iris video decoder driver

[Stefan Schmidt]

Hello Johan,

On Thu, 9 Jan 2025 at 15:58, Johan Hovold <johan@xxxxxxxxxx> wrote:
>
> [ +CC: Bjorn ]
>
> On Thu, Dec 12, 2024 at 05:21:22PM +0530, Dikshita Agarwal wrote:
> > Introduce support for Qualcomm new video acceleration hardware i.e.
> > iris, used for video stream decoding.
>
> > Note: A harmless onetime error log "Lucid PLL latch failed. Output may
> > be unstable!" is seen during bootup.  It doesn't impact any video
> > usecase and is currently under discussion.
>
> This could be an indication that some resources are not described
> correctly and could potentially require both binding and driver changes
> to address.
>
> This is also something which could cause trouble later (e.g. during
> suspend) even if you manage to get the clock running after boot.
>
> Generally, you should not be introducing any new warnings; they are
> there to let you know that something is wrong.
>
> Where is this issue being discussed?
>
> I think we at least need a public analysis and understanding of the
> problem before merging this.

Taniya Das proposed a patchset to reconfigure PLL in the clk-alpha-pll
which allows the videocc-sm8550 driver to configure it correctly.
https://lore.kernel.org/linux-arm-msm/20250113-support-pll-reconfigure-v1-0-1fae6bc1062d@xxxxxxxxxxx/T/

I tested the Iris driver with this patchset and I am no longer seeing
the Lucid PLL latch failed warning.

regards
Stefan Schmidt