[PATCH v13 6/6] iommu/arm-smmu: add support for PRR bit setup

Bibek Kumar Patro quic_bibekkum at quicinc.com
Mon Jul 15 04:01:28 PDT 2024



On 7/11/2024 3:31 AM, Konrad Dybcio wrote:
> On 10.07.2024 7:01 PM, Rob Clark wrote:
>> On Tue, Jul 9, 2024 at 12:43 PM Bibek Kumar Patro
>> <quic_bibekkum at quicinc.com> wrote:
> 
> [...]
> 
>> If there is a clean break, such as all smmu-500 have PRR and all
>> smmu-v2 do not, then it would be reasonable to use the compat strings.
>> If not, I think we need a different way.
> 
> if (a reserved-memory region is passed in dt) {
> 	init_prr()
> }
> 

This would have been a straight forward way to pass as a check for PRR
support, but as I mentioned in the above thread reserved-memory region 
is not required if gfx/drm allocates the page.
So I think compatible string would be more approachable way?

Thanks & regards,
Bibek

> Konrad



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