[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 at gmail.com>
>>>> ---
>>> 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 at gmail.com>