[PATCH 6/7] drm/i915: Restart RPS using the same RP_CONTROL as from initialisation

[Chris Wilson]

During initialisation, we set different flags for different
architectures - these should be preserved when we reload the RPS
thresholds. If we use a mmio read, it will first ensure that the
threshold registers are written before we apply the latch in RP_CONTROL.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Cc: stable at vger.kernel.org
---
 drivers/gpu/drm/i915/intel_pm.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 3041cd4988a6..d37e95b3525d 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4884,13 +4884,9 @@ static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
 		      GT_INTERVAL_FROM_US(dev_priv,
 					  ei_down * threshold_down / 100));
 
+	/* Restart RPS to reload the thresholds */
 	I915_WRITE_FW(GEN6_RP_CONTROL,
-		      GEN6_RP_MEDIA_TURBO |
-		      GEN6_RP_MEDIA_HW_NORMAL_MODE |
-		      GEN6_RP_MEDIA_IS_GFX |
-		      GEN6_RP_ENABLE |
-		      GEN6_RP_UP_BUSY_AVG |
-		      GEN6_RP_DOWN_IDLE_AVG);
+		      I915_READ_FW(GEN6_RP_CONTROL) | GEN6_RP_ENABLE);
 
 	intel_uncore_forcewake_put__locked(dev_priv, FORCEWAKE_ALL);
 	spin_unlock_irq(&dev_priv->uncore.lock);
-- 
2.11.0