Re: [Intel-gfx] [PATCH 2/2] drm/i915/pmu: Use correct requested freq for SLPC

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 04/03/2023 01:27, Ashutosh Dixit wrote:
> SLPC does not use 'struct intel_rps'. Use UNSLICE_RATIO bits from

Would it be more accurate to say 'SLPC does not use rps->cur_freq' 
rather than it not using struct intel_rps?

Fixes: / stable ? CI chances of catching this?

> GEN6_RPNSWREQ for SLPC. See intel_rps_get_requested_frequency.
> 
> Bspec: 52745
> 
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
> ---
>   drivers/gpu/drm/i915/i915_pmu.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
> index f0a1e36915b8..5ee836610801 100644
> --- a/drivers/gpu/drm/i915/i915_pmu.c
> +++ b/drivers/gpu/drm/i915/i915_pmu.c
> @@ -394,8 +394,13 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns)
>   		 * frequency. Fortunately, the read should rarely fail!
>   		 */
>   		val = intel_rps_get_cagf(rps, intel_rps_read_rpstat_fw(rps));
> -		if (!val)
> -			val = rps->cur_freq;
> +		if (!val) {
> +			if (intel_uc_uses_guc_slpc(&gt->uc))
> +				val = intel_rps_read_punit_req(rps) >>
> +						GEN9_SW_REQ_UNSLICE_RATIO_SHIFT;
> +			else
> +				val = rps->cur_freq;
> +		}

That's a bunch of duplication from intel_rps.c so perhaps the 
appropriate helpers should be exported (some way) from there.

Regards,

Tvrtko

>   
>   		add_sample_mult(&pmu->sample[__I915_SAMPLE_FREQ_ACT],
>   				intel_gpu_freq(rps, val), period_ns / 1000);