[PATCH] drm/i915: Program the correct frequencies into the interrupt thresholds

[chris at chris-wilson.co.uk (Chris Wilson)]

The only question is the units for the interrupt thresholds. Everywhere
we treat the min/max frequencies in units of 50MHz. However, indications
seem to be that we expect the thresholds in units of 100MHz - though
currently we program them using the 50MHz values.

Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_pm.c |   28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 73cf311..bb10582 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2187,7 +2187,6 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 	u32 gt_perf_status = I915_READ(GEN6_GT_PERF_STATUS);
 	u32 pcu_mbox, rc6_mask = 0;
 	u32 gtfifodbg;
-	int cur_freq, min_freq, max_freq;
 	int rc6_mode;
 	int i;
 
@@ -2208,6 +2207,14 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 
 	gen6_gt_force_wake_get(dev_priv);
 
+	rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
+	gt_perf_status = I915_READ(GEN6_GT_PERF_STATUS);
+
+	/* In units of 100MHz */
+	dev_priv->max_delay = rp_state_cap & 0xff;
+	dev_priv->min_delay = (rp_state_cap & 0xff0000) >> 16;
+	dev_priv->cur_delay = (gt_perf_status & 0xff00) >> 8;
+
 	/* disable the counters and set deterministic thresholds */
 	I915_WRITE(GEN6_RC_CONTROL, 0);
 
@@ -2255,8 +2262,8 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 
 	I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 1000000);
 	I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
-		   18 << 24 |
-		   6 << 16);
+		   dev_priv->max_delay << 24 |
+		   dev_priv->min_delay << 16);
 	I915_WRITE(GEN6_RP_UP_THRESHOLD, 10000);
 	I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 1000000);
 	I915_WRITE(GEN6_RP_UP_EI, 100000);
@@ -2282,10 +2289,6 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 		     500))
 		DRM_ERROR("timeout waiting for pcode mailbox to finish\n");
 
-	min_freq = (rp_state_cap & 0xff0000) >> 16;
-	max_freq = rp_state_cap & 0xff;
-	cur_freq = (gt_perf_status & 0xff00) >> 8;
-
 	/* Check for overclock support */
 	if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) == 0,
 		     500))
@@ -2296,14 +2299,13 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 		     500))
 		DRM_ERROR("timeout waiting for pcode mailbox to finish\n");
 	if (pcu_mbox & (1<<31)) { /* OC supported */
-		max_freq = pcu_mbox & 0xff;
+		dev_priv->max_delay = pcu_mbox & 0xff;
 		DRM_DEBUG_DRIVER("overclocking supported, adjusting frequency max to %dMHz\n", pcu_mbox * 50);
-	}
 
-	/* In units of 100MHz */
-	dev_priv->max_delay = max_freq;
-	dev_priv->min_delay = min_freq;
-	dev_priv->cur_delay = cur_freq;
+		I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
+			   dev_priv->max_delay << 24 |
+			   dev_priv->min_delay << 16);
+	}
 
 	/* requires MSI enabled */
 	I915_WRITE(GEN6_PMIER,
-- 
1.7.10