Re: [PATCH 2/2] cpufreq: cppc: cppc_cpufreq_get_rate() returns zero in all error cases.

From: Viresh Kumar
Date: Tue Aug 15 2023 - 23:44:09 EST


On 15-08-23, 09:40, Liao Chang wrote:
> The cpufreq framework used to use the zero of return value to reflect
> the cppc_cpufreq_get_rate() had failed to get current frequecy and treat
> all positive integer to be succeed. Since cppc_get_perf_ctrs() returns a
> negative integer in error case, so it is better to convert the value to
> zero as the return value of cppc_cpufreq_get_rate().
>
> Signed-off-by: Liao Chang <liaochang1@xxxxxxxxxx>
> ---
> drivers/cpufreq/cppc_cpufreq.c | 4 ++--
> include/linux/cpufreq.h | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index 796bc3e19f77..1cdef2da1ea4 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -854,13 +854,13 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
>
> ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0);
> if (ret)
> - return ret;
> + return 0;
>
> udelay(2); /* 2usec delay between sampling */
>
> ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t1);
> if (ret)
> - return ret;
> + return 0;
>
> delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0,
> &fb_ctrs_t1);
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 172ff51c1b2a..99da27466b8f 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -370,7 +370,7 @@ struct cpufreq_driver {
> int (*target_intermediate)(struct cpufreq_policy *policy,
> unsigned int index);
>
> - /* should be defined, if possible */
> + /* should be defined, if possible, return 0 on error */
> unsigned int (*get)(unsigned int cpu);
>
> /* Called to update policy limits on firmware notifications. */

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

--
viresh