On 01/04/2021 10:19, Rodrigo Vivi wrote:
On Wed, Mar 31, 2021 at 11:18:50AM +0100, Tvrtko Ursulin wrote:
From: Tvrtko Ursulin tvrtko.ursulin@intel.com
RC6 support cannot be simply established by looking at the static device HAS_RC6() flag. There are cases which disable RC6 at driver load time so use the status of those check when deciding whether to enumerate the rc6 counter.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Reported-by: Eero T Tamminen eero.t.tamminen@intel.com
drivers/gpu/drm/i915/i915_pmu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index 41651ac255fa..a75cd1db320b 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -476,6 +476,8 @@ engine_event_status(struct intel_engine_cs *engine, static int config_status(struct drm_i915_private *i915, u64 config) {
- struct intel_gt *gt = &i915->gt;
- switch (config) { case I915_PMU_ACTUAL_FREQUENCY: if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
@@ -489,7 +491,7 @@ config_status(struct drm_i915_private *i915, u64 config) case I915_PMU_INTERRUPTS: break; case I915_PMU_RC6_RESIDENCY:
if (!HAS_RC6(i915))
if (!gt->rc6.supported)Is this really going to remove any confusion? Right now it is there but with residency 0, but after this change the event is not there anymore so I wonder if we are not just changing to a different kind of confusion on users.
I think it is possible to argue both ways.
1) HAS_RC6 means hardware has RC6 so if we view PMU as very low level we can say always export it.
If i915 had to turn it off (rc6->supported == false) due firmware or GVT-g, then we could say reporting zero RC6 is accurate in that sense. Only the reason "why it is zero" is missing for PMU users.
2) Or if we go with this patch we could say that presence of the PMU metric means RC6 is active and enabled, while absence means it is either not supported due platform (or firmware) or how the platform is getting used (GVT-g).
So I think patch is a bit better. I don't see it is adding more confusion.
return -ENODEV;would a different return help somehow?
Like distinguishing between not theoretically possible to support on this GPU, versus not active? Perhaps.. suggest an errno? :)
Regards,
Tvrtko
break;case I915_PMU_SOFTWARE_GT_AWAKE_TIME:
2.27.0
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