Re: [PATCH v2 2/2] cpufreq: Wire-up arch-flavored freq info into cpufreq_verify_current_freq

Rafael J. Wysocki
2023-12-06T20:41:22Z

On Mon, Nov 27, 2023 at 5:09 PM Beata Michalska <beata.michalska@arm.com> wrote:
>
> From: Sumit Gupta <sumitg@nvidia.com>
>
> When available, use arch_freq_get_on_cpu to obtain current frequency
> (usually an average reported over given period of time)
> to better align the cpufreq's view on the current state of affairs.

And why is this a good idea?

Any problem statement?

> This also automatically pulls in the update for cpuinfo_cur_freq sysfs
> attribute, aligning it with the scaling_cur_freq one, and thus providing
> consistent view on relevant platforms.

I have no idea what the above is supposed to mean, sorry.

> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
> [BM: Subject & commit msg]
> Signed-off-by: Beata Michalska <beata.michalska@arm.com>
> ---
> drivers/cpufreq/cpufreq.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 8c4f9c2f9c44..109559438f45 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1756,7 +1756,8 @@ static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, b
> {
> unsigned int new_freq;
>
> - new_freq = cpufreq_driver->get(policy->cpu);
> + new_freq = arch_freq_get_on_cpu(policy->cpu);
> + new_freq = new_freq ?: cpufreq_driver->get(policy->cpu);

Please don't use ?: in general and it is not even useful here AFAICS.

What would be wrong with

new_freq = arch_freq_get_on_cpu(policy->cpu);
if (!new_freq)
new_freq = cpufreq_driver->get(policy->cpu);

?

> if (!new_freq)
> return 0;
>
> --