[PATCH 4/5] drm/i915/gt: Restore aggressive post-boost downclocking

[Chris Wilson]

We reduced the clocks slowly after a boost event based on the
observation that the smoothness of animations suffered. However, since
reducing the evalution intervals, we should be able to respond to the
rapidly fluctuating workload of a simple desktop animation and so
restore the more aggressive downclocking.

References: 2a8862d2f3da4f2576c34f66647127b3bb77c316
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_rps.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
index c8134f112e99..d4928f967079 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -1558,20 +1558,6 @@ static void rps_work(struct work_struct *work)
 		goto unlock;
 	}
 
-	rps->last_adj = adj;
-
-	/*
-	 * Limit deboosting and boosting to keep ourselves at the extremes
-	 * when in the respective power modes (i.e. slowly decrease frequencies
-	 * while in the HIGH_POWER zone and slowly increase frequencies while
-	 * in the LOW_POWER zone). On idle, we will hit the timeout and drop
-	 * to the next level quickly, and conversely if busy we expect to
-	 * hit a waitboost and rapidly switch into max power.
-	 */
-	if ((adj < 0 && rps->power.mode == HIGH_POWER) ||
-	    (adj > 0 && rps->power.mode == LOW_POWER))
-		rps->last_adj = 0;
-
 	/*
 	 * sysfs frequency limits may have snuck in while
 	 * servicing the interrupt
@@ -1581,8 +1567,9 @@ static void rps_work(struct work_struct *work)
 
 	if (intel_rps_set(rps, new_freq)) {
 		drm_dbg(&i915->drm, "Failed to set new GPU frequency\n");
-		rps->last_adj = 0;
+		adj = 0;
 	}
+	rps->last_adj = adj;
 
 unlock:
 	mutex_unlock(&rps->lock);
-- 
2.20.1