Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > Quoting Mika Kuoppala (2018-06-05 17:03:57) >> There is a problem with kbl up to rev E0 where a heavy >> memory/fabric traffic from adjacent engine(s) can cause an engine >> reset to fail. This traffic can be from normal memory accesses >> or it can be from heavy polling on a semaphore wait. >> >> For engine hogging causing a fail, we already fallback to >> full reset. Which effectively stops all engines and thus >> we only add a workaround documentation. >> >> For the semaphore wait loop poll case, we add one microsecond >> poll interval to semaphore wait to guarantee bandwidth for >> the reset preration. The side effect is that we make semaphore >> completion latencies also 1us longer. >> >> v2: Let full reset handle the adjacent engine idling (Chris) >> >> References: https://bugs.freedesktop.org/show_bug.cgi?id=106684 >> References: VTHSD#2227190, HSDES#1604216706, BSID#0917 >> Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> >> --- >> diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c >> index b1ab56a1ec31..5655d39c65cb 100644 >> --- a/drivers/gpu/drm/i915/intel_workarounds.c >> +++ b/drivers/gpu/drm/i915/intel_workarounds.c >> @@ -666,6 +666,15 @@ static void kbl_gt_workarounds_apply(struct drm_i915_private *dev_priv) >> I915_WRITE(GEN9_GAMT_ECO_REG_RW_IA, >> I915_READ(GEN9_GAMT_ECO_REG_RW_IA) | >> GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS); >> + >> + /* WaKBLVECSSemaphoreWaitPoll:kbl */ >> + if (IS_KBL_REVID(dev_priv, KBL_REVID_A0, KBL_REVID_E0)) { > > Hmm, what revision was production? Just checking we need to ship this > w/a... The bspec list of revs seems outdated so can't trust that blindly but already 0x1 is not preprod on that list. Also found nuc in lab which is 0x02. -Mika _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
