[Intel-gfx] [PATCH 2/2] drm/i915/gt: Leave rps->cur_freq on unpark

[Chris Wilson]

Don't override our previous frequency we used after parking, and avoid
continually spiking back to the efficient frequency for mostly idle
workloads. Trust our ability to autotune across a workload switch.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti at intel.com>
Cc: Lyude Paul <lyude at redhat.com>
---
 drivers/gpu/drm/i915/gt/intel_rps.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
index 50884aeac49c..487c89593125 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -187,10 +187,8 @@ static void gen5_rps_init(struct intel_rps *rps)
 		fmax, fmin, fstart);
 
 	rps->min_freq = fmax;
+	rps->efficient_freq = fstart;
 	rps->max_freq = fmin;
-
-	rps->idle_freq = rps->min_freq;
-	rps->cur_freq = rps->idle_freq;
 }
 
 static unsigned long
@@ -726,7 +724,6 @@ void intel_rps_unpark(struct intel_rps *rps)
 
 	WRITE_ONCE(rps->active, true);
 
-	freq = max(rps->cur_freq, rps->efficient_freq),
 	freq = clamp(freq, rps->min_freq_softlimit, rps->max_freq_softlimit);
 	intel_rps_set(rps, freq);
 
@@ -1672,7 +1669,7 @@ void intel_rps_init(struct intel_rps *rps)
 	/* Finally allow us to boost to max by default */
 	rps->boost_freq = rps->max_freq;
 	rps->idle_freq = rps->min_freq;
-	rps->cur_freq = rps->idle_freq;
+	rps->cur_freq = rps->efficient_freq; /* start in the middle */
 
 	rps->pm_intrmsk_mbz = 0;
 
-- 
2.20.1