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

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Mon, 06 Mar 2023 03:10:24 -0800, Tvrtko Ursulin wrote:
>

Hi Tvrtko,

> 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?

No actually SLPC maintains a separate 'struct intel_guc_slpc' and does not
use 'struct intel_rps' at all so all of 'struct intel_rps' is 0.

> Fixes: / stable ? CI chances of catching this?

Same issue as Patch 1, I have answered this there.

> > 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.

This is also addressed in the new series:

https://patchwork.freedesktop.org/series/114814/

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

Thanks.
--
Ashutosh