Re: [PATCH 13/16] drm/msm/a8xx: Implement IFPC support for A840

[Akhil P Oommen]

On 3/24/2026 3:43 PM, Konrad Dybcio wrote:
> On 3/23/26 9:12 PM, Akhil P Oommen wrote:
>> Implement pwrup reglist support and add the necessary register
>> configurations to enable IFPC support on A840
>>
>> Signed-off-by: Akhil P Oommen <akhilpo@xxxxxxxxxxxxxxxx>
>> ---
> 
> [...]
> 
>> +	for (u32 pipe_id = PIPE_BR; pipe_id <= PIPE_DDE_BV; pipe_id++) {
>> +		for (i = 0; i < dyn_pwrup_reglist->count; i++) {
>> +			if ((dyn_pwrup_reglist->regs[i].pipe & BIT(pipe_id)) == 0)
> 
> that's a nitty pet peeve, but I'd check for if (!(...)) instead
> 
> [...]
> 
>> +				continue;
>> +			*dest++ = A8XX_CP_APERTURE_CNTL_HOST_PIPEID(pipe_id);
>> +			*dest++ = dyn_pwrup_reglist->regs[i].offset;
>> +			*dest++ = a8xx_read_pipe_slice(gpu,
>> +						       pipe_id,
>> +						       a8xx_get_first_slice(a6xx_gpu),
> 
> Only the first slice?

Yeah. I think we just need to pass a valid slice id and
a8xx_get_first_slice() will always return a valid one.

> 
> [...]
> 
>> +	/* Lo address */
>> +	OUT_RING(ring, lower_32_bits(a6xx_gpu->pwrup_reglist_iova));
>> +	/* Hi address */
>> +	OUT_RING(ring, upper_32_bits(a6xx_gpu->pwrup_reglist_iova));
>> +
>> +	/* Enable dyn pwrup list with triplets (offset, value, pipe) */
>> +	OUT_RING(ring, BIT(31));
> 
> I believe you need to patch OUT_PKT7() with the updated cmd count

Thanks. Fixed. I guess the mask was probably helping when I tested.

-Akhil.

> 
> Konrad