diff --git a/sys/dev/drm2/i915/intel_iic.c b/sys/dev/drm2/i915/intel_iic.c
index 412349c..3a1b34d 100644
--- a/sys/dev/drm2/i915/intel_iic.c
+++ b/sys/dev/drm2/i915/intel_iic.c
@@ -128,10 +128,13 @@ intel_iic_reset(struct drm_device *dev)
 	struct drm_i915_private *dev_priv;
 
 	dev_priv = dev->dev_private;
-	if (HAS_PCH_SPLIT(dev))
+	if (HAS_PCH_SPLIT(dev)) {
 		I915_WRITE(PCH_GMBUS0, 0);
-	else
+		I915_WRITE(PCH_GMBUS4, 0);
+	} else {
 		I915_WRITE(GMBUS0, 0);
+		I915_WRITE(GMBUS4, 0);
+	}
 }
 
 static int