| Message ID | 20200114105648.2172026-2-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/i915/pmu: Correct the rc6 offset upon enabling | expand |
On 14/01/2020 10:56, Chris Wilson wrote: > On suspend, the rc6 residency counters (stored in HW registers) will be > lost and cleared. However, we keep track of the rc6 residency to provide > a continuous 64b sampling, and if we see the HW value go backwards, we > assume it overflowed and add on 32b/40b -- an interesting artifact when > sampling across suspend. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > --- > drivers/gpu/drm/i915/gt/intel_rc6.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c > index 9e303c29d6e3..04eeb7740e53 100644 > --- a/drivers/gpu/drm/i915/gt/intel_rc6.c > +++ b/drivers/gpu/drm/i915/gt/intel_rc6.c > @@ -542,6 +542,8 @@ void intel_rc6_init(struct intel_rc6 *rc6) > > void intel_rc6_sanitize(struct intel_rc6 *rc6) > { > + memset(rc6->prev_hw_residency, 0, sizeof(rc6->prev_hw_residency)); > + > if (rc6->enabled) { /* unbalanced suspend/resume */ > rpm_get(rc6); > rc6->enabled = false; > Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c index 9e303c29d6e3..04eeb7740e53 100644 --- a/drivers/gpu/drm/i915/gt/intel_rc6.c +++ b/drivers/gpu/drm/i915/gt/intel_rc6.c @@ -542,6 +542,8 @@ void intel_rc6_init(struct intel_rc6 *rc6) void intel_rc6_sanitize(struct intel_rc6 *rc6) { + memset(rc6->prev_hw_residency, 0, sizeof(rc6->prev_hw_residency)); + if (rc6->enabled) { /* unbalanced suspend/resume */ rpm_get(rc6); rc6->enabled = false;
On suspend, the rc6 residency counters (stored in HW registers) will be lost and cleared. However, we keep track of the rc6 residency to provide a continuous 64b sampling, and if we see the HW value go backwards, we assume it overflowed and add on 32b/40b -- an interesting artifact when sampling across suspend. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> --- drivers/gpu/drm/i915/gt/intel_rc6.c | 2 ++ 1 file changed, 2 insertions(+)