[Intel-gfx] [PATCH v1 1/2] drm/i915: Enabling RC6 immediately instead of enabling via delayed work item

[sagar.a.kamble at intel.com]

From: Sagar Kamble <sagar.a.kamble at intel.com>

RC6 was getting enabled through deferred work item which was scheduled
after 1s. This will keep render and media well ON for 1s. Since RC6 enabling does
not involve PCU communication, processing time in intel_enable_gt_powersave will
not be increased. Enabling RC6 immediately will help power gate render and media
well immediately that will save power.

Signed-off-by: Akash Goel <akash.goel at intel.com>
Signed-off-by: Sagar Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 88 ++++++++++++++++++++++++++++-------------
 1 file changed, 61 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 9af0af4..1fb3084 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5276,11 +5276,11 @@ static void valleyview_cleanup_gt_powersave(struct drm_device *dev)
 	valleyview_cleanup_pctx(dev);
 }
 
-static void cherryview_enable_rps(struct drm_device *dev)
+static void cherryview_enable_rc6(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *ring;
-	u32 gtfifodbg, val, rc6_mode = 0, pcbr;
+	u32 gtfifodbg, rc6_mode = 0, pcbr;
 	int i;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
@@ -5294,10 +5294,10 @@ static void cherryview_enable_rps(struct drm_device *dev)
 
 	cherryview_check_pctx(dev_priv);
 
-	/* 1a & 1b: Get forcewake during program sequence. Although the driver
-	 * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
-	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
-
+	/*
+	 * Assuming RC6 disabled by uncore_sanitize we dont need to do
+	 * force wake get/put here.
+	 */
 	/* 2a: Program RC6 thresholds.*/
 	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
@@ -5324,6 +5324,18 @@ static void cherryview_enable_rps(struct drm_device *dev)
 		rc6_mode = GEN6_RC_CTL_EI_MODE(1);
 
 	I915_WRITE(GEN6_RC_CONTROL, rc6_mode);
+}
+
+static void cherryview_enable_rps(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 val;
+
+	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
+
+	/* 1a & 1b: Get forcewake during program sequence. Although the driver
+	 * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
+	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
 
 	/* 4 Program defaults and thresholds for RPS*/
 	I915_WRITE(GEN6_RP_UP_THRESHOLD, 59400);
@@ -5367,11 +5379,11 @@ static void cherryview_enable_rps(struct drm_device *dev)
 	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
 }
 
-static void valleyview_enable_rps(struct drm_device *dev)
+static void valleyview_enable_rc6(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *ring;
-	u32 gtfifodbg, val, rc6_mode = 0;
+	u32 gtfifodbg, rc6_mode = 0;
 	int i;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
@@ -5384,25 +5396,10 @@ static void valleyview_enable_rps(struct drm_device *dev)
 		I915_WRITE(GTFIFODBG, gtfifodbg);
 	}
 
-	/* If VLV, Forcewake all wells, else re-direct to regular path */
-	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
-
-	I915_WRITE(GEN6_RP_UP_THRESHOLD, 59400);
-	I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 245000);
-	I915_WRITE(GEN6_RP_UP_EI, 66000);
-	I915_WRITE(GEN6_RP_DOWN_EI, 350000);
-
-	I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
-	I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 0xf4240);
-
-	I915_WRITE(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_CONT);
-
+	/*
+	 * Assuming RC6 disabled by uncore_sanitize we dont need to do
+	 * force wake get/put here.
+	 */
 	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 0x00280000);
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000);
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25);
@@ -5425,6 +5422,32 @@ static void valleyview_enable_rps(struct drm_device *dev)
 	intel_print_rc6_info(dev, rc6_mode);
 
 	I915_WRITE(GEN6_RC_CONTROL, rc6_mode);
+}
+
+static void valleyview_enable_rps(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 val;
+
+	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
+
+	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
+
+	I915_WRITE(GEN6_RP_UP_THRESHOLD, 59400);
+	I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 245000);
+	I915_WRITE(GEN6_RP_UP_EI, 66000);
+	I915_WRITE(GEN6_RP_DOWN_EI, 350000);
+
+	I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
+	I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 0xf4240);
+
+	I915_WRITE(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_CONT);
 
 	val = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS);
 
@@ -6295,6 +6318,17 @@ void intel_enable_gt_powersave(struct drm_device *dev)
 		mutex_unlock(&dev->struct_mutex);
 	} else if (INTEL_INFO(dev)->gen >= 6) {
 		/*
+		 * Enabling RC6 for VLV & CHV here itself and only deferring turbo
+		 * enabling.
+		 */
+		mutex_lock(&dev_priv->rps.hw_lock);
+		if (IS_CHERRYVIEW(dev))
+			cherryview_enable_rc6(dev);
+		else if (IS_VALLEYVIEW(dev))
+			valleyview_enable_rc6(dev);
+		mutex_unlock(&dev_priv->rps.hw_lock);
+
+		/*
 		 * PCU communication is slow and this doesn't need to be
 		 * done at any specific time, so do this out of our fast path
 		 * to make resume and init faster.
-- 
1.8.5