Quoting Mika Kuoppala (2018-06-06 09:40:11) > 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 The bspec list of revs seems outdated so can't trust that blindly 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. Acked-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Care to update intel_detect_preproduction_hw() ? -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
