[Intel-gfx] [RFC][PATCH 1/2] drm/i915: Don't increase the GPU frequency from the delayed VLV rps timer

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

There's little point in increasing the GPU frequency from the delayed
rps work on VLV. Now when the GPU is idle, the GPU frequency actually
keeps dropping gradually until it hits the minimum, whereas previously
it just ping-ponged constantly between RPe and RPe-1.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 96cfb3e..eaf0fa2 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3464,7 +3464,8 @@ static void vlv_rps_timer_work(struct work_struct *work)
 	 * min freq available.
 	 */
 	mutex_lock(&dev_priv->rps.hw_lock);
-	valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
+	if (dev_priv->rps.cur_delay > dev_priv->rps.rpe_delay)
+		valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
 	mutex_unlock(&dev_priv->rps.hw_lock);
 }
 
-- 
1.8.1.5