Re: [PATCH v2] drm/i915/selftests: Add delay to stabilize frequency in live_rps_power

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 03 Dec 2024, Sk Anirban <sk.anirban@intel.com> wrote:
> Add delays to allow frequency stabilization before power measurement
> to fix sporadic power conservation issues in live_rps_power test.

Looks like band-aid. What's the root cause?

BR,
Jani.

>
> v2:
>   - Move delay to respective function (Badal)
>
> Signed-off-by: Sk Anirban <sk.anirban@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/selftest_rps.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.c b/drivers/gpu/drm/i915/gt/selftest_rps.c
> index dcef8d498919..c207a4fb03bf 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_rps.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_rps.c
> @@ -1125,6 +1125,7 @@ static u64 measure_power(struct intel_rps *rps, int *freq)
>  static u64 measure_power_at(struct intel_rps *rps, int *freq)
>  {
>  	*freq = rps_set_check(rps, *freq);
> +	msleep(100);
>  	return measure_power(rps, freq);
>  }

-- 
Jani Nikula, Intel