Re: [PATCH 1/3] ACPI: CPPC: Refactor boost ratio handling

[Rafael J. Wysocki (Intel)]

On Tue, Sep 1, 2026 at 5:28 PM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:
>
>
>
> On 9/1/26 04:31, K Prateek Nayak wrote:
> > On 9/1/2026 1:14 AM, Mario Limonciello wrote:
> >> +int amd_get_max_frequency(unsigned int cpu)
> >> +{
> >> +    enum x86_topology_cpu_type type = cpu_data(cpu).topo.cpu_type;
> >> +    const struct x86_cpu_id *id = x86_match_cpu(amd_zen6_client_ids);
> >> +    const struct amd_max_freq *max_freq;
> >> +
> >> +    if (!id)
> >> +            return -ENODEV;
> >> +
> >> +    max_freq = (const struct amd_max_freq *)id->driver_data;
> >> +
> >> +    switch (type) {
> >> +    case TOPO_CPU_TYPE_PERFORMANCE:
> >> +            return max_freq->performance;
> >> +    case TOPO_CPU_TYPE_EFFICIENCY:
> >> +            return max_freq->efficiency;
> >> +    case TOPO_CPU_TYPE_LOW_POWER:
> >> +            return max_freq->low_power;
> >> +    default:
> >> +            break;
> >> +    }
> >> +
> >> +    return -EINVAL;
> >
> > nit. Since we don't really propagate the error codes returned
> > by amd_get_max_frequency(), maybe we can return 0 instead of
> > -ENODEV, -EINVAL and the callers can simply do:
> >
> >      max_freq = amd_get_max_frequency(cpu);
> >      if (!max_freq)
> >           max_freq = /* Fallback */;
> >
> > similar to get_max_boost_ratio() pattern. No strong feelings
> > either way.
> >
>
> OK.  Will adjust for next version.
>
> >> +}
> >> +EXPORT_SYMBOL_GPL(amd_get_max_frequency);

Please note though that all CPPC-related material is gated on this patch series:

https://lore.kernel.org/linux-acpi/20260830115644.2056983-1-christian.loehle@xxxxxxx/

and there are other multiple series already waiting.

That queue needs to be flushed I'm afraid.