Re: [RFC 0/2] Stop the abuse of Linux-* _OSI strings

From: Karol Herbst
Date: Fri Aug 19 2022 - 11:46:04 EST


On Fri, Aug 19, 2022 at 4:25 PM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:
>
> 3 _OSI strings were introduced in recent years that were intended
> to workaround very specific problems found on specific systems.
>
> The idea was supposed to be that these quirks were only used on
> those systems, but this proved to be a bad assumption. I've found
> at least one system in the wild where the vendor using the _OSI
> string doesn't match the _OSI string and the neither does the use.
>
> So this brings a good time to review keeping those strings in the kernel.
> There are 3 strings that were introduced:
>
> Linux-Dell-Video
> -> Intended for systems with NVIDIA cards that didn't support RTD3
> Linux-Lenovo-NV-HDMI-Audio
> -> Intended for powering on NVIDIA HDMI device
> Linux-HPI-Hybrid-Graphics
> -> Intended for changing dGPU output
>
> AFAIK the first string is no longer relevant as nouveau now supports
> RTD3. If that's wrong, this can be changed for the series.
>

Nouveau always supported RTD3, because that's mainly a kernel feature.
When those were introduced we simply had a bug only hit on a few
systems. And instead of helping us to debug this, this workaround was
added :( We were not even asked about this.

I am a bit curious about the other two though as I am not even sure
they are needed at all as we put other work arounds in place. @Lyude
Paul might know more about these.