Re: [PATCH] cpufreq: conservative: Take limits changes into account properly

From: Viresh Kumar
Date: Tue Oct 16 2018 - 05:52:33 EST


On 15-10-18, 23:21, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> If the policy limits change between invocations of cs_dbs_update(),
> the requested frequency value stored in dbs_info may not be updated
> and the function may use a stale value of it next time. Moreover, if
> idle periods are takem into account by cs_dbs_update(), the requested
> frequency value stored in dbs_info may be below the min policy limit,
> which is incorrect.
>
> To fix these problems, always update the requested frequency value
> in dbs_info along with the local copy of it when the previous
> requested frequency is beyond the policy limits and avoid decreasing
> the requested frequency below the min policy limit when taking
> idle periods into account.
>
> Reported-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@xxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
> drivers/cpufreq/cpufreq_conservative.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)

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

--
viresh