Re: [PATCH 3/4] platform/x86/intel/pmc: Always dump LPM status regs on unsuccessful paths

[Xi Pardee <xi.pardee@linux.intel.com>]

On 10/14/2025 12:58 PM, Guilherme G. Piccoli wrote:
> Thanks Xi! Response inline:
>
> On 14/10/2025 16:29, Xi Pardee wrote:
>> [...]
>>
>> Entering the S0ix state requires the system to reach the deepest package
>> C-state, PC10. If the system fails to achieve PC10 residency during
>> suspend, the slps0_dbg_maps data becomes irrelevant and may mislead
>> users. For this reason, the driver hides this information when PC10
>> residency is not attained.
>>
> Indeed, I agree - this is even mentioned in the spec.
>
> But the patch here doesn't change that (or shouldn't - except if I did
> something wrong heh).
>
> The idea of this patch is to dump the LPM registers in any failure path,
> the ones printed by pmc_core_lpm_display() - not related with the
> slps0_dbg_maps.
>
> Lemme know your thoughts on this.
> Cheers,
>
>
> Guilherme
When the system fails to enter the S0ix state during suspend, there are 
two scenarios to consider:
1. If the system achieves PC10 residency, debugging S0ix can focus on 
the information provided by slps0_dbg_maps or lpm_sts.
2. If the system does not achieve PC10 residency, the PMC core driver 
supplies package C-state residency information instead.
It is important to note that the data presented by 
pmc_core_lpm_display() is only relevant when PC10 residency has been 
attained.
This difference helps ensure that users are provided with accurate and 
meaningful information relevant to the power state achieved during suspend.
Thanks!
Xi
>