Re: [PATCH 2/2] drm/i915/guc/slpc: Add helper function slpc_measure_power

["Nilawar, Badal" <badal.nilawar@xxxxxxxxx>]

On 13-01-2025 15:29, Sk Anirban wrote:
> Previously, the RPS function was being used, which utilizes
> raw frequency to calculate measured power. This commit introduces
> a dedicated function specifically for measuring power in SLPC,
> ensuring more accurate and reliable power measurements.
>
> Signed-off-by: Sk Anirban <sk.anirban@xxxxxxxxx>
> ---
>   drivers/gpu/drm/i915/gt/selftest_slpc.c | 17 ++++++++++++++++-
>   1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/selftest_slpc.c b/drivers/gpu/drm/i915/gt/selftest_slpc.c
> index 4ecc4ae74a54..cb5d5e2c5dbe 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_slpc.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_slpc.c
> @@ -95,6 +95,21 @@ static int slpc_restore_freq(struct intel_guc_slpc *slpc, u32 min, u32 max)
>   	return 0;
>   }
>   
> +static u64 slpc_measure_power(struct intel_rps *rps, int *freq)
> +{
> +	u64 x[5];
> +	int i;
> +
> +	for (i = 0; i < 5; i++)
> +		x[i] = __measure_power(5);
> +
> +	*freq = (*freq + intel_rps_read_actual_frequency(rps)) / 2;
> +
> +	/* A simple triangle filter for better result stability */
> +	sort(x, 5, sizeof(*x), cmp_u64, NULL);
> +	return div_u64(x[1] + 2 * x[2] + x[3], 4);
> +}
> +
>   static u64 measure_power_at_freq(struct intel_gt *gt, int *freq, u64 *power)
>   {
>   	int err = 0;
> @@ -103,7 +118,7 @@ static u64 measure_power_at_freq(struct intel_gt *gt, int *freq, u64 *power)
>   	if (err)
>   		return err;
>   	*freq = intel_rps_read_actual_frequency(&gt->rps);
> -	*power = measure_power(&gt->rps, freq);
> +	*power = slpc_measure_power(&gt->rps, freq);

Reviewed-by: Badal Nilawar <badal.nilawar@xxxxxxxxx>

Regards,
Badal

>   
>   	return err;
>   }