[PATCH] drm/etnaviv: Create an accel device node if compute-only

[Daniel Stone]

Hi,

On Wed, 26 Jun 2024 at 09:28, Lucas Stach <l.stach at pengutronix.de> wrote:
> Mesa doesn't cope right now. Mostly because of the renderonly thing
> where we magically need to match render devices to otherwise render
> incapable KMS devices. The way this matching works is that the
> renderonly code tries to open a screen on a rendernode and if that
> succeeds we treat it as the matching render device.
>
> The core of the issue is that we have no way of specifying which kind
> of screen we need at that point, i.e. if the screen should have 3D
> render capabilities or if compute-only or even NN-accel-only would be
> okay. So we can't fail screen creation if there is no 3D engine, as
> this would break the teflon case, which needs a screen for the NN
> accel, but once we successfully create a screen reanderonly might treat
> the thing as a rendering device.
> So we are kind of stuck here between breaking one or the other use-
> case. I'm leaning heavily into the direction of just fixing Mesa, so we
> can specify the type of screen we need at creation time to avoid the
> renderonly issue, porting this change as far back as reasonably
> possible and file old userspace into shit-happens.

Yeah, honestly this sounds like the best solution to me too.

Cheers,
Daniel