From 7fec9c6ed7d5c6337bd87062b25d8a35e532f309 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sun, 22 Mar 2020 16:32:24 +0000 Subject: [PATCH] drm/i915/gt: Treat idling as a RPS downclock event If we park/unpark faster than we can respond to RPS events, we never will process a downclock event after expiring a waitboost, and thus we will forever restart the GPU at max clocks even if the workload switches and doesn't justify full power. Closes: https://gitlab.freedesktop.org/drm/intel/issues/1500 Fixes: 60057c8cc5ff ("drm/i915: Extract GT render power state management") Signed-off-by: Chris Wilson Cc: Andi Shyti Cc: Lyude Paul Reviewed-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20200322163225.28791-1-chris@chris-wilson.co.uk Cc: # v5.5+ --- drivers/gpu/drm/i915/gt/intel_rps.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c index 7bf631ca560b7..2d906db2da577 100644 --- a/drivers/gpu/drm/i915/gt/intel_rps.c +++ b/drivers/gpu/drm/i915/gt/intel_rps.c @@ -771,6 +771,19 @@ void intel_rps_park(struct intel_rps *rps) intel_uncore_forcewake_get(rps_to_uncore(rps), FORCEWAKE_MEDIA); rps_set(rps, rps->idle_freq, false); intel_uncore_forcewake_put(rps_to_uncore(rps), FORCEWAKE_MEDIA); + + /* + * Since we will try and restart from the previously requested + * frequency on unparking, treat this idle point as a downclock + * interrupt and reduce the frequency for resume. If we park/unpark + * more frequently than the rps worker can run, we will not respond + * to any EI and never see a change in frequency. + * + * (Note we accommodate Cherryview's limitation of only using an + * even bin by applying it to all.) + */ + rps->cur_freq = + max_t(int, round_down(rps->cur_freq - 1, 2), rps->min_freq); } void intel_rps_boost(struct i915_request *rq) -- 2.39.5