Re: [PATCH v6 3/4] drm: Expand max DRM device number to full MINORBITS

From: Simon Ser
Date: Fri Jul 28 2023 - 10:23:13 EST


On Thursday, July 27th, 2023 at 14:01, Christian König <christian.koenig@xxxxxxx> wrote:

> > We do need patches to stop trying to infer the node type from the minor
> > in libdrm, though. Emil has suggested using sysfs, which we already do
> > in a few places in libdrm.
>
> That sounds like a really good idea to me as well.
>
> But what do we do with DRM_MAX_MINOR? Change it or keep it and say apps
> should use drmGetDevices2() like Emil suggested?

DRM_MAX_MINOR has been bumped to 64 now.

With the new minor allocation scheme, DRM_MAX_MINOR is meaningless
because there is no "max minor per type" concept anymore: the minor no
longer contains the type.

So I'd suggest leaving it as-is (so that old apps still continue to
work on systems with < 64 devices like they do today) and mark it as
deprecated.