Re: [PATCH RFC 10/13] drm/msm: initialize LPAC ring

[Anna Maniscalco]

On 7/6/26 11:56 PM, Akhil P Oommen wrote:
> On 7/6/2026 4:37 PM, Anna Maniscalco wrote:
> > On 7/6/26 10:44 AM, Konrad Dybcio wrote:
> > > On 7/5/26 9:13 PM, Anna Maniscalco wrote:
> > > > Program all the register needed to start up LPAC and send initialization
> > > > sequence.
> > > >
> > > > Additionally, now that the LPAC ring is live, make the code aware of it.
> > > >
> > > > Signed-off-by: Anna Maniscalco <anna.maniscalco2000@xxxxxxxxx>
> > > > ---
> > > I believe some/all of these writes need to be guarded by if (has_lpac),
> > > as many GPUs lack these registers and there may be side effects on
> > > others
> > That's correct yeah. I'm not sure what has_lpac should be though.
> >
> > Something we add to catalog? Or checking if it is a gen that has LPAC?
> We can introduce a new QUIRK (ADRENO_QUIRK_LPAC?).
>
> > > [...]
> > >
> > > >            a6xx_gpu->shadow = msm_gem_kernel_new(gpu->dev,
> > > > -                              sizeof(u32) * gpu->nr_rings,
> > > > +                              sizeof(u32) * (gpu->nr_rings + !!gpu-
> > > > > lpac_rb),
> > > Should we rename nr_rings to something like nr_XXX_rings
> > > where XXX is some uarch-generic (i.e. not SQE because we also
> > > support pre-a6xx) name for the main number cruncher?
> > Qualcom calls it GC so nr_gc_rings perhaps?
> How about nr_gfx_rings as those rings can handle graphics workload?
That could be more intuitive yeah
> -Akhil.
>
> > > Konrad
> >
> > Best regards,


Best regards,
--
Anna Maniscalco <anna.maniscalco2000@xxxxxxxxx>