diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3eb899bbb7aa..2d618865b3dd 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2228,6 +2228,7 @@ struct i915_oa_ops {
 
 struct intel_cdclk_state {
 	unsigned int cdclk, vco, ref;
+	u8 voltage_level;
 };
 
 struct drm_i915_private {
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index d8a4b523d878..e8b4e19e978b 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1707,17 +1707,34 @@ void cnl_uninit_cdclk(struct drm_i915_private *dev_priv)
 }
 
 /**
- * intel_cdclk_state_compare - Determine if two CDCLK states differ
+ * intel_cdclk_needs_modeset - Determine if two CDCLK states require a modeset on all pipes
  * @a: first CDCLK state
  * @b: second CDCLK state
  *
  * Returns:
- * True if the CDCLK states are identical, false if they differ.
+ * True if the CDCLK states require pipes to be off during reprogramming, false if not.
  */
-bool intel_cdclk_state_compare(const struct intel_cdclk_state *a,
+bool intel_cdclk_needs_modeset(const struct intel_cdclk_state *a,
 			       const struct intel_cdclk_state *b)
 {
-	return memcmp(a, b, sizeof(*a)) == 0;
+	return a->cdclk != b->cdclk ||
+		a->vco != b->vco ||
+		a->ref != b->ref;
+}
+
+/**
+ * intel_cdclk_changed - Determine if two CDCLK states are different
+ * @a: first CDCLK state
+ * @b: second CDCLK state
+ *
+ * Returns:
+ * True if the CDCLK states don't match, false if they do.
+ */
+bool intel_cdclk_changed(const struct intel_cdclk_state *a,
+			 const struct intel_cdclk_state *b)
+{
+	return intel_cdclk_needs_modeset(a, b) ||
+		a->voltage_level != b->voltage_level;
 }
 
 /**
@@ -1731,15 +1748,15 @@ bool intel_cdclk_state_compare(const struct intel_cdclk_state *a,
 void intel_set_cdclk(struct drm_i915_private *dev_priv,
 		     const struct intel_cdclk_state *cdclk_state)
 {
-	if (intel_cdclk_state_compare(&dev_priv->cdclk.hw, cdclk_state))
+	if (!intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_state))
 		return;
 
 	if (WARN_ON_ONCE(!dev_priv->display.set_cdclk))
 		return;
 
-	DRM_DEBUG_DRIVER("Changing CDCLK to %d kHz, VCO %d kHz, ref %d kHz\n",
+	DRM_DEBUG_DRIVER("Changing CDCLK to %d kHz, VCO %d kHz, ref %d kHz, voltage_level %d\n",
 			 cdclk_state->cdclk, cdclk_state->vco,
-			 cdclk_state->ref);
+			 cdclk_state->ref, cdclk_state->voltage_level);
 
 	dev_priv->display.set_cdclk(dev_priv, cdclk_state);
 }
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a83e18c72f7b..c6ca73479f6f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11956,16 +11956,16 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
 		 * holding all the crtc locks, even if we don't end up
 		 * touching the hardware
 		 */
-		if (!intel_cdclk_state_compare(&dev_priv->cdclk.logical,
-					       &intel_state->cdclk.logical)) {
+		if (intel_cdclk_changed(&dev_priv->cdclk.logical,
+					&intel_state->cdclk.logical)) {
 			ret = intel_lock_all_pipes(state);
 			if (ret < 0)
 				return ret;
 		}
 
 		/* All pipes must be switched off while we change the cdclk. */
-		if (!intel_cdclk_state_compare(&dev_priv->cdclk.actual,
-					       &intel_state->cdclk.actual)) {
+		if (intel_cdclk_needs_modeset(&dev_priv->cdclk.actual,
+					      &intel_state->cdclk.actual)) {
 			ret = intel_modeset_all_pipes(state);
 			if (ret < 0)
 				return ret;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5d77f75a9f9c..94c193961824 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1323,8 +1323,10 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv);
 void intel_update_max_cdclk(struct drm_i915_private *dev_priv);
 void intel_update_cdclk(struct drm_i915_private *dev_priv);
 void intel_update_rawclk(struct drm_i915_private *dev_priv);
-bool intel_cdclk_state_compare(const struct intel_cdclk_state *a,
+bool intel_cdclk_needs_modeset(const struct intel_cdclk_state *a,
 			       const struct intel_cdclk_state *b);
+bool intel_cdclk_changed(const struct intel_cdclk_state *a,
+			 const struct intel_cdclk_state *b);
 void intel_set_cdclk(struct drm_i915_private *dev_priv,
 		     const struct intel_cdclk_state *cdclk_state);
 
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index d169bfb98368..01cd705f605b 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -715,7 +715,8 @@ static void gen9_dc_off_power_well_enable(struct drm_i915_private *dev_priv,
 	gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
 
 	dev_priv->display.get_cdclk(dev_priv, &cdclk_state);
-	WARN_ON(!intel_cdclk_state_compare(&dev_priv->cdclk.hw, &cdclk_state));
+	/* Can't read out voltage_level so can't use intel_cdclk_changed() */
+	WARN_ON(intel_cdclk_needs_modeset(&dev_priv->cdclk.hw, &cdclk_state));
 
 	gen9_assert_dbuf_enabled(dev_priv);
 
