Re: [PATCH V3 4/4] cpufreq: CPPC: Add support for frequency invariance

From: Ionela Voinescu
Date: Thu Jun 24 2021 - 05:48:19 EST


Hey,

On Monday 21 Jun 2021 at 14:49:37 (+0530), Viresh Kumar wrote:
> The Frequency Invariance Engine (FIE) is providing a frequency scaling
> correction factor that helps achieve more accurate load-tracking.
[..]
> +static void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
> +{
> + struct cppc_freq_invariance *cppc_fi;
> + int cpu;
> +
> + if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
> + return;
> +
> + /* policy->cpus will be empty here, use related_cpus instead */
> + topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_CPPC, policy->related_cpus);
> +
> + for_each_cpu(cpu, policy->related_cpus) {
> + cppc_fi = &per_cpu(cppc_freq_inv, cpu);

Do you think it might be worth having here something like:

if (!cppc_fi->cpu_data)
continue;

This would be to protect against cases where the platform does not boot
with all CPUs or the module is loaded after some have already been
offlined. Unlikely, but..

> + irq_work_sync(&cppc_fi->irq_work);
> + kthread_cancel_work_sync(&cppc_fi->work);
> + }
> +}

The rest of the code is almost the same as the original, so that is all
from me :).

Thanks,
Ionela.