[Intel-gfx] [PATCH 06/10] drm/i915: Rearrange RPS frequency calculation

[Chris Wilson]

The goal is to refactor the Cherryview special casing to only be in a
single location. To do so we need to compute the desired adjustment and
then tweak it for Cherryview. This has the minor side-effect of making
sure we set adj to 0 if we directly update the target frequency.
Ensuring that the RPS constants are correct for Cherryview is outside
the scope of this function

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_irq.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 60ca89986499..586625b78cbb 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1420,21 +1420,20 @@ static void gen6_pm_rps_work(struct work_struct *work)
 	mutex_lock(&dev_priv->rps.hw_lock);
 
 	adj = dev_priv->rps.last_adj;
+	new_delay = dev_priv->rps.cur_freq;
 	if (pm_iir & GEN6_PM_RP_UP_THRESHOLD) {
 		if (adj > 0)
 			adj *= 2;
-		else {
-			/* CHV needs even encode values */
-			adj = IS_CHERRYVIEW(dev_priv->dev) ? 2 : 1;
-		}
-		new_delay = dev_priv->rps.cur_freq + adj;
-
+		else
+			adj = 1;
 		/*
 		 * For better performance, jump directly
 		 * to RPe if we're below it.
 		 */
-		if (new_delay < dev_priv->rps.efficient_freq)
+		if (new_delay < dev_priv->rps.efficient_freq - adj) {
 			new_delay = dev_priv->rps.efficient_freq;
+			adj = 0;
+		}
 	} else if (pm_iir & GEN6_PM_RP_DOWN_TIMEOUT) {
 		if (dev_priv->rps.cur_freq > dev_priv->rps.efficient_freq)
 			new_delay = dev_priv->rps.efficient_freq;
@@ -1446,15 +1445,17 @@ static void gen6_pm_rps_work(struct work_struct *work)
 	} else if (pm_iir & GEN6_PM_RP_DOWN_THRESHOLD) {
 		if (adj < 0)
 			adj *= 2;
-		else {
-			/* CHV needs even encode values */
-			adj = IS_CHERRYVIEW(dev_priv->dev) ? -2 : -1;
-		}
-		new_delay = dev_priv->rps.cur_freq + adj;
+		else
+			adj = -1;
 	} else { /* unknown event */
-		new_delay = dev_priv->rps.cur_freq;
+		adj = 0;
 	}
 
+	/* CHV needs even encode values */
+	if (IS_CHERRYVIEW(dev_priv->dev))
+		adj <<= 1;
+	new_delay += adj;
+
 	/* sysfs frequency interfaces may have snuck in while servicing the
 	 * interrupt
 	 */
-- 
2.1.0