Re: [PATCH 2/7] irqchip/irq-qcom-mpm: Register MPM under CPU cluster power domain

[Konrad Dybcio]

On 8/3/26 12:58 PM, Sneh Mankad wrote:
> 
> 
> On 15-Jul-26 4:04 PM, Stephan Gerhold wrote:
>> On Wed, Jul 15, 2026 at 11:46:58AM +0200, Konrad Dybcio wrote:
>>> On 7/13/26 12:25 PM, Sneh Mankad wrote:

[...]

>> I don't think this fallback is relevant for the non-PSCI QC platforms,
>> for the following reasons:
>>
>>  - They don't define the MPM.
>>  - They don't support cluster idle upstream, so they don't need to
>>    define the MPM. They can't reach the idle state where it would become
>>    relevant.
>>  - The setup for cluster idle without PSCI is essentially equivalent to
>>    OSI, except that the SPM/SAW driver needs to program the idle state
>>    to enter. There is one SPM/SAW for every idle domain (e.g. on
>>    MSM8939: 2x4 CPU, 2x Cluster, 1x System). You can just model the
>>    SPM/SAW instances as power domains to get the same setup as PSCI OSI
>>    (I had a draft for this at some point). So if someone ever implements
>>    this, we should be able to use the same approach as for PSCI OSI.
>>
>> I'm not aware of non-OSI PSCI platforms with MPM either, so I'm not sure
>> when this fallback would be used.
>>
>> We probably do need some fallback for the old sm6375/agatii DTBs though.
> 
> Yes Stephan, this fallback will be required for RPM targets that do not have
> power-domains property mentioned to facilitate the RPM notification in cluster
> idle states, including agatti and sm6375.

Will it be able to do anything useful though? Because if it were, we
might as well not change the bindings. Now don't get me wrong, I'm in
favor of straightening them out, but this sounds a bit unclear

Because if we lose nothing, we may simply not carry the fallback (i.e.
provide the interrupt part of mpm without the cluster notif)

Konrad