Re: [PATCH v4] x86, sched: Fix the AMD CPPC maximum perf on some specific generations

From: Ingo Molnar
Date: Wed May 12 2021 - 16:34:36 EST



* Huang Rui <ray.huang@xxxxxxx> wrote:

> Some AMD Ryzen generations has different calculation method on maximum
> perf. 255 is not for all asics, some specific generations should use 166
> as the maximum perf. Otherwise, it will report incorrect frequency value
> like below:
>
> ~ → lscpu | grep MHz
> CPU MHz: 3400.000
> CPU max MHz: 7228.3198
> CPU min MHz: 2200.0000

It would have been useful to also quote the 'after' part.

> +u32 amd_get_highest_perf(void)
> +{
> + struct cpuinfo_x86 *c = &boot_cpu_data;
> +
> + if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
> + (c->x86_model >= 0x70 && c->x86_model < 0x80)))
> + return 166;
> +
> + if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
> + (c->x86_model >= 0x40 && c->x86_model < 0x70)))
> + return 166;

I fixed these stray 4-space tabs.

Looks good otherwise - queued up in tip:sched/urgent.

Thanks,

Ingo