Patch "drm/i915: introduce intel_has_sagv()" has been added to the 4.8-stable tree

@@ -13891,7 +13891,7 @@ static void intel_atomic_commit_tail(str
 		 * SKL workaround: bspec recommends we disable the SAGV when we
 		 * have more then one pipe enabled
 		 */
-		if (IS_SKYLAKE(dev_priv) && !intel_can_enable_sagv(state))
+		if (!intel_can_enable_sagv(state))
 			intel_disable_sagv(dev_priv);
 
 		intel_modeset_verify_disabled(dev);

@@ -13949,8 +13949,7 @@ static void intel_atomic_commit_tail(str
 		intel_modeset_verify_crtc(crtc, old_crtc_state, crtc->state);
 	}
 
-	if (IS_SKYLAKE(dev_priv) && intel_state->modeset &&
-	    intel_can_enable_sagv(state))
+	if (intel_state->modeset && intel_can_enable_sagv(state))
 		intel_enable_sagv(dev_priv);
 
 	drm_atomic_helper_commit_hw_done(state);

@@ -2878,6 +2878,13 @@ skl_wm_plane_id(const struct intel_plane
 	}
 }
 
+static bool
+intel_has_sagv(struct drm_i915_private *dev_priv)
+{
+	return IS_SKYLAKE(dev_priv) &&
+	       dev_priv->sagv_status != I915_SAGV_NOT_CONTROLLED;
+}
+
 /*
  * SAGV dynamically adjusts the system agent voltage and clock frequencies
  * depending on power and performance requirements. The display engine access

@@ -2894,8 +2901,10 @@ intel_enable_sagv(struct drm_i915_privat
 {
 	int ret;
 
-	if (dev_priv->sagv_status == I915_SAGV_NOT_CONTROLLED ||
-	    dev_priv->sagv_status == I915_SAGV_ENABLED)
+	if (!intel_has_sagv(dev_priv))
+		return 0;
+
+	if (dev_priv->sagv_status == I915_SAGV_ENABLED)
 		return 0;
 
 	DRM_DEBUG_KMS("Enabling the SAGV\n");

@@ -2943,8 +2952,10 @@ intel_disable_sagv(struct drm_i915_priva
 {
 	int ret, result;
 
-	if (dev_priv->sagv_status == I915_SAGV_NOT_CONTROLLED ||
-	    dev_priv->sagv_status == I915_SAGV_DISABLED)
+	if (!intel_has_sagv(dev_priv))
+		return 0;
+
+	if (dev_priv->sagv_status == I915_SAGV_DISABLED)
 		return 0;
 
 	DRM_DEBUG_KMS("Disabling the SAGV\n");

@@ -2985,6 +2996,9 @@ bool intel_can_enable_sagv(struct drm_at
 	enum pipe pipe;
 	int level, plane;
 
+	if (!intel_has_sagv(dev_priv))
+		return false;
+
 	/*
 	 * SKL workaround: bspec recommends we disable the SAGV when we have
 	 * more then one pipe enabled