drm/i915: Removed the read of RP_STATE_CAP from sysfs/debugfs functions

The frequency values(Rp0, Rp1, Rpn) reported by RP_STATE_CAP register
are stored, initially by the Driver, inside the dev_priv->rps structure.
Since these values are expected to remain same throughout, there is no real
need to read this register, on dynamic basis, from certain debugfs/sysfs
functions and the values can be instead retrieved from the dev_priv->rps
structure when needed.
For the i915_frequency_info debugfs interface, the frequency values from the
RP_STATE_CAP register only should be used, to indicate the actual Hw state,
since it is principally used for the debugging purpose.

v2: Reverted the changes in i915_frequency_info function, to continue report
    back the frequency values, as per the actual Hw state (Chris)

Signed-off-by: Akash Goel <akash.goel@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -4180,7 +4180,7 @@ i915_max_freq_set(void *data, u64 val)
 {
 	struct drm_device *dev = data;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 rp_state_cap, hw_max, hw_min;
+	u32 hw_max, hw_min;
 	int ret;
 
 	if (INTEL_INFO(dev)->gen < 6)
@@ -4197,18 +4197,10 @@ i915_max_freq_set(void *data, u64 val)
 	/*
 	 * Turbo will still be enabled, but won't go above the set value.
 	 */
-	if (IS_VALLEYVIEW(dev)) {
-		val = intel_freq_opcode(dev_priv, val);
+	val = intel_freq_opcode(dev_priv, val);
 
-		hw_max = dev_priv->rps.max_freq;
-		hw_min = dev_priv->rps.min_freq;
-	} else {
-		val = intel_freq_opcode(dev_priv, val);
-
-		rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
-		hw_max = dev_priv->rps.max_freq;
-		hw_min = (rp_state_cap >> 16) & 0xff;
-	}
+	hw_max = dev_priv->rps.max_freq;
+	hw_min = dev_priv->rps.min_freq;
 
 	if (val < hw_min || val > hw_max || val < dev_priv->rps.min_freq_softlimit) {
 		mutex_unlock(&dev_priv->rps.hw_lock);
@@ -4255,7 +4247,7 @@ i915_min_freq_set(void *data, u64 val)
 {
 	struct drm_device *dev = data;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 rp_state_cap, hw_max, hw_min;
+	u32 hw_max, hw_min;
 	int ret;
 
 	if (INTEL_INFO(dev)->gen < 6)
@@ -4272,18 +4264,10 @@ i915_min_freq_set(void *data, u64 val)
 	/*
 	 * Turbo will still be enabled, but won't go below the set value.
 	 */
-	if (IS_VALLEYVIEW(dev)) {
-		val = intel_freq_opcode(dev_priv, val);
+	val = intel_freq_opcode(dev_priv, val);
 
-		hw_max = dev_priv->rps.max_freq;
-		hw_min = dev_priv->rps.min_freq;
-	} else {
-		val = intel_freq_opcode(dev_priv, val);
-
-		rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
-		hw_max = dev_priv->rps.max_freq;
-		hw_min = (rp_state_cap >> 16) & 0xff;
-	}
+	hw_max = dev_priv->rps.max_freq;
+	hw_min = dev_priv->rps.min_freq;
 
 	if (val < hw_min || val > hw_max || val > dev_priv->rps.max_freq_softlimit) {
 		mutex_unlock(&dev_priv->rps.hw_lock);

drivers/gpu/drm/i915/i915_sysfs.c

@@ -487,38 +487,17 @@ static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr
 	struct drm_minor *minor = dev_to_drm_minor(kdev);
 	struct drm_device *dev = minor->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 val, rp_state_cap;
-	ssize_t ret;
-
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
-	if (ret)
-		return ret;
-	intel_runtime_pm_get(dev_priv);
-	rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
-	intel_runtime_pm_put(dev_priv);
-	mutex_unlock(&dev->struct_mutex);
+	u32 val;
 
-	if (attr == &dev_attr_gt_RP0_freq_mhz) {
-		if (IS_VALLEYVIEW(dev))
-			val = intel_gpu_freq(dev_priv, dev_priv->rps.rp0_freq);
-		else
-			val = intel_gpu_freq(dev_priv,
-					     ((rp_state_cap & 0x0000ff) >> 0));
-	} else if (attr == &dev_attr_gt_RP1_freq_mhz) {
-		if (IS_VALLEYVIEW(dev))
-			val = intel_gpu_freq(dev_priv, dev_priv->rps.rp1_freq);
-		else
-			val = intel_gpu_freq(dev_priv,
-					     ((rp_state_cap & 0x00ff00) >> 8));
-	} else if (attr == &dev_attr_gt_RPn_freq_mhz) {
-		if (IS_VALLEYVIEW(dev))
-			val = intel_gpu_freq(dev_priv, dev_priv->rps.min_freq);
-		else
-			val = intel_gpu_freq(dev_priv,
-					     ((rp_state_cap & 0xff0000) >> 16));
-	} else {
+	if (attr == &dev_attr_gt_RP0_freq_mhz)
+		val = intel_gpu_freq(dev_priv, dev_priv->rps.rp0_freq);
+	else if (attr == &dev_attr_gt_RP1_freq_mhz)
+		val = intel_gpu_freq(dev_priv, dev_priv->rps.rp1_freq);
+	else if (attr == &dev_attr_gt_RPn_freq_mhz)
+		val = intel_gpu_freq(dev_priv, dev_priv->rps.min_freq);
+	else
 		BUG();
-	}
+
 	return snprintf(buf, PAGE_SIZE, "%d\n", val);
 }