[Intel-gfx] [PATCH 02/30] drm/i915: We implement WaGsvBringDownFreqInRc6:vlv

[ville.syrjala at linux.intel.com]

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

WaGsvBringDownFreqInRc6:vlv tells us to switch to RPe from a timer.
Which is what we do.

There's another workaround by the name of
WaGsvBringDownFreqBeforeRenderRC6:vlv which instructs us to keep render
always awake, and then drop the freq to 200MHz and allow RC6 just before
entering D3. That doesn't sound as nice, especially since we don't
have runtime PM yet.

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

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 15c9c3b..a160b4c 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3451,6 +3451,8 @@ static void vlv_rps_timer_work(struct work_struct *work)
 	 * Vmin we were shooting for.  That should give us better
 	 * perf when we come back out of RC6 than if we used the
 	 * min freq available.
+	 *
+	 * WaGsvBringDownFreqInRc6:vlv
 	 */
 	mutex_lock(&dev_priv->rps.hw_lock);
 	if (dev_priv->rps.cur_delay > dev_priv->rps.rpe_delay)
-- 
1.8.1.5