Re: [Intel-gfx] [PATCH 19/20] drm/i915/lmem: don't treat small BAR as an error

Thomas Hellström
2022-02-03T13:56:25Z

On Thu, 2022-02-03 at 11:18 +0000, Matthew Auld wrote:
> On 03/02/2022 09:48, Thomas Hellström wrote:
> >
> > On 1/26/22 16:21, Matthew Auld wrote:
> > > Just pass along the probed io_size. The backend should be able to
> > > utilize the entire range here, even if some of it is non-
> > > mappable.
> > Changes here LGTM.
> > >
> > > It does leave open with what to do with stolen local-memory.
> >
> > Are objects in stolen local required to be mappable?
>
>  From a quick look I don't really see such users on discrete, outside
> of
> maybe intelfb_create(), where I guess the initial fb might be located
> in
> stolen on DG1. But from DG2+ it looks like it will just be located in
> normal LMEM. For that I was thinking we add something like
> i915_gem_object_create_region_at(), and somehow wire that up to the
> {fpfn, lpfn}...

So we could then skip STOLEN completely on DG2+? Could we then also do
the same on DG1, at least assuming that creating and pinning an object
for that initial fb would be done before any other pinning into LMEM?

/Thomas