| Message ID | 20191108085626.32429-3-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] drm/i915/icl: Refine PG_HYSTERESIS | expand |
Quoting Chris Wilson (2019-11-08 08:56:24) > We want to avoid taking forcewake when querying the performance stats, > as we wish to avoid perturbing the system under observation. (And with > the forcewake being kept alive for 1ms after use, sampling the frequency > from a timer keeps forcewake 60% active.) Oops, rc6 was reported as 60% active => fw 40% active. -Chris
On 08/11/2019 08:56, Chris Wilson wrote: > We want to avoid taking forcewake when querying the performance stats, > as we wish to avoid perturbing the system under observation. (And with > the forcewake being kept alive for 1ms after use, sampling the frequency > from a timer keeps forcewake 60% active.) > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > --- > drivers/gpu/drm/i915/i915_pmu.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c > index 05395015d1f2..dbde80a376cb 100644 > --- a/drivers/gpu/drm/i915/i915_pmu.c > +++ b/drivers/gpu/drm/i915/i915_pmu.c > @@ -366,8 +366,12 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns) > > val = rps->cur_freq; > if (intel_gt_pm_get_if_awake(gt)) { > - val = intel_uncore_read_notrace(uncore, GEN6_RPSTAT1); > - val = intel_get_cagf(rps, val); > + u32 stat; > + > + stat = intel_uncore_read_fw(uncore, GEN6_RPSTAT1); > + if (stat) > + val = intel_get_cagf(rps, stat); > + > intel_gt_pm_put(gt); > } > > Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index 05395015d1f2..dbde80a376cb 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -366,8 +366,12 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns) val = rps->cur_freq; if (intel_gt_pm_get_if_awake(gt)) { - val = intel_uncore_read_notrace(uncore, GEN6_RPSTAT1); - val = intel_get_cagf(rps, val); + u32 stat; + + stat = intel_uncore_read_fw(uncore, GEN6_RPSTAT1); + if (stat) + val = intel_get_cagf(rps, stat); + intel_gt_pm_put(gt); }
We want to avoid taking forcewake when querying the performance stats, as we wish to avoid perturbing the system under observation. (And with the forcewake being kept alive for 1ms after use, sampling the frequency from a timer keeps forcewake 60% active.) Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> --- drivers/gpu/drm/i915/i915_pmu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)