Re: [PATCH v12 00/18] drm: Add Samsung MIPI DSIM bridge

Rasmus Villemoes
2023-02-24T14:09:56Z

On 22/02/2023 11.05, Frieder Schrempf wrote:

> The NXP kernel is completely different. AFAIK it uses the component
> helpers to bundle all subdrivers from a central driver
> (display-subsystem). This is not how the mainline approach using the
> bridge driver interface works. So you can't compare them.
>
> Did you look at this extensive thread with findings from Adam?
>
> https://lore.kernel.org/lkml/CAHCN7xJ=N1vWVTBjArskJ59fyaLzmAGWfc0E=_iGizrDNR_Udw@mail.gmail.com/
>
> It is related to HDMI, but I guess a lot of things are valid for DP, too.
>
> Anyway, we need to get this series merged. Otherwise we can't work on
> fixing all the other issues on top.

Alright, I finally managed to get the imx8mm-dsi-v12 branch (commit
fdde97c7d553) to work, by modifying Marek's patch for enabling the
lcdif->mipi pipeline a little. The end result is in
https://github.com/Villemoes/linux/tree/imx8mp-mipi . There are also a
few cherry-picks of by-now-upstream patches to imx8mp.dtsi included.

It works on our custom hardware, with the ti,sn65dsi86 mipi->eDP bridge.

It does not seem to work on the imx8mp-evk with the adv7535 hdmi bridge
daughter board, but that's probably just as much the fault of the
adv7535 driver as anything in the SOC - it's impossible to get a real
data sheet for that thing, and there's no end of random patches floating
around, with the NXP kernel doing completely their own thing. So I've
given up on getting that to work.

Rasmus