From d39da686c2f3b8518b6933951d53891aa83227d6 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 18 Dec 2019 09:35:04 +0000 Subject: [PATCH] drm/i915/gt: Ratelimit display power w/a For very light workloads that frequently park, acquiring the display power well (required to prevent the dmc from trashing the system) takes longer than the execution. A good example is the igt_coherency selftest, which is slowed down by an order of magnitude in the worst case with powerwell cycling. To prevent frequent cycling, while keeping our fast soft-rc6, use a timer to delay release of the display powerwell. Fixes: 311770173fac ("drm/i915/gt: Schedule request retirement when timeline idles") References: https://gitlab.freedesktop.org/drm/intel/issues/848 Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191218093504.3477048-1-chris@chris-wilson.co.uk (cherry picked from commit 81ff52b705775433a955b2746d37b87bdc89a3d0) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/gt/intel_gt_pm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_pm.c index a459a42ad5c2..7e64b7d7d330 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.c @@ -94,8 +94,9 @@ static int __gt_park(struct intel_wakeref *wf) intel_uncore_forcewake_put(&i915->uncore, FORCEWAKE_ALL); } + /* Defer dropping the display power well for 100ms, it's slow! */ GEM_BUG_ON(!wakeref); - intel_display_power_put(i915, POWER_DOMAIN_GT_IRQ, wakeref); + intel_display_power_put_async(i915, POWER_DOMAIN_GT_IRQ, wakeref); i915_globals_park();