[PATCH] drm/i915: Update rps interrupt limits

[jeff.mcgee@intel.com]

From: Jeff McGee <jeff.mcgee@intel.com>

sysfs changes to rps min and max delay were only triggering an update
of the rps interrupt limits if the active delay required an update.
This change ensures that interrupt limits are always updated.

OTC-Tracker: VIZ-3144
Change-Id: I0adb8d968190e138382b449dcec7e297743b9cca
Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
---
 drivers/gpu/drm/i915/i915_sysfs.c | 10 ++++++++++
 drivers/gpu/drm/i915/intel_pm.c   | 10 +++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 05d8b16..6f34e3a 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -349,6 +349,11 @@ static ssize_t gt_max_freq_mhz_store(struct device *kdev,
 		else
 			gen6_set_rps(dev, val);
 	}
+	else if (!IS_VALLEYVIEW(dev))
+		/* We still need gen6_set_rps to process the new max_delay
+		   and update the interrupt limits even though frequency
+		   request is unchanged. */
+		gen6_set_rps(dev, dev_priv->rps.cur_delay);
 
 	mutex_unlock(&dev_priv->rps.hw_lock);
 
@@ -418,6 +423,11 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
 		else
 			gen6_set_rps(dev, val);
 	}
+	else if (!IS_VALLEYVIEW(dev))
+		/* We still need gen6_set_rps to process the new min_delay
+		   and update the interrupt limits even though frequency
+		   request is unchanged. */
+		gen6_set_rps(dev, dev_priv->rps.cur_delay);
 
 	mutex_unlock(&dev_priv->rps.hw_lock);
 
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 172efa0..447c70d 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3538,6 +3538,9 @@ static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
 	dev_priv->rps.last_adj = 0;
 }
 
+/* gen6_set_rps is called to update the frequency request, but should also be
+ * called when the range (min_delay and max_delay) is modified so that we can
+ * update the GEN6_RP_INTERRUPT_LIMITS register accordingly. */
 void gen6_set_rps(struct drm_device *dev, u8 val)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3546,8 +3549,13 @@ void gen6_set_rps(struct drm_device *dev, u8 val)
 	WARN_ON(val > dev_priv->rps.max_delay);
 	WARN_ON(val < dev_priv->rps.min_delay);
 
-	if (val == dev_priv->rps.cur_delay)
+	if (val == dev_priv->rps.cur_delay) {
+		/* min/max delay may still have been modified so be sure to
+		 * write the limits value */
+		I915_WRITE(GEN6_RP_INTERRUPT_LIMITS, limits);
+
 		return;
+	}
 
 	gen6_set_rps_thresholds(dev_priv, val);
 
-- 
1.8.4.2