On Thu, Feb 22, 2024 at 9:35 AM Shivnandan Kumar
<quic_kshivnan@xxxxxxxxxxx> wrote:
>
> Resolving a frequency to an efficient one should not transgress policy->max
> (which can be set for thermal reason) and policy->min. Currently there is
> possibility where scaling_cur_freq can exceed scaling_max_freq when
> scaling_max_freq is inefficient frequency. Add additional check to ensure
> that resolving a frequency will respect policy->min/max.
>
> Fixes: 1f39fa0dccff ("cpufreq: Introducing CPUFREQ_RELATION_E")
> Signed-off-by: Shivnandan Kumar <quic_kshivnan@xxxxxxxxxxx>
> ---
> include/linux/cpufreq.h | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index afda5f24d3dd..42d98b576a36 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -1021,6 +1021,19 @@ static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy,
> efficiencies);
> }
>
> +static inline bool cpufreq_table_index_is_in_limits(struct cpufreq_policy *policy,
> + int idx)
This is not really about the index only, but about the frequency at
that index too, so I'd call the function differently.
> +{
> + unsigned int freq;
> +
> + if (idx < 0)
> + return false;
> +
> + freq = policy->freq_table[idx].frequency;
> +
> + return (freq == clamp_val(freq, policy->min, policy->max));
Redundant outer parens.
> +}
> +
> static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
> unsigned int target_freq,
> unsigned int relation)
> @@ -1054,7 +1067,10 @@ static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
> return 0;
> }
>
> - if (idx < 0 && efficiencies) {
> + /*
> + * Limit frequency index to honor policy->min/max
> + */
This comment need not be multi-line.
> + if (!cpufreq_table_index_is_in_limits(policy, idx) && efficiencies) {
> efficiencies = false;
> goto retry;
> }
> --
Thanks!
