diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c b/drivers/gpu/drm/i915/display/intel_display_power_well.c
index 719f58e43269..3abfb17f8988 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
@@ -257,8 +257,9 @@ aux_ch_to_digital_port(struct intel_display *display,
 	return NULL;
 }
 
-static enum phy icl_aux_pw_to_phy(struct intel_display *display,
-				  const struct i915_power_well *power_well)
+static struct intel_encoder *
+icl_aux_pw_to_encoder(struct intel_display *display,
+		      const struct i915_power_well *power_well)
 {
 	enum aux_ch aux_ch = icl_aux_pw_to_ch(power_well);
 	struct intel_digital_port *dig_port = aux_ch_to_digital_port(display, aux_ch);
@@ -270,7 +271,23 @@ static enum phy icl_aux_pw_to_phy(struct intel_display *display,
 	 * as HDMI-only and routed to a combo PHY, the encoder either won't be
 	 * present at all or it will not have an aux_ch assigned.
 	 */
-	return dig_port ? intel_encoder_to_phy(&dig_port->base) : PHY_NONE;
+	return dig_port ? &dig_port->base : NULL;
+}
+
+static enum phy icl_aux_pw_to_phy(struct intel_display *display,
+				  const struct i915_power_well *power_well)
+{
+	struct intel_encoder *encoder = icl_aux_pw_to_encoder(display, power_well);
+
+	return encoder ? intel_encoder_to_phy(encoder) : PHY_NONE;
+}
+
+static bool icl_aux_pw_is_tc_phy(struct intel_display *display,
+				 const struct i915_power_well *power_well)
+{
+	struct intel_encoder *encoder = icl_aux_pw_to_encoder(display, power_well);
+
+	return encoder && intel_encoder_is_tc(encoder);
 }
 
 static void hsw_wait_for_power_well_enable(struct intel_display *display,
@@ -569,9 +586,7 @@ static void
 icl_aux_power_well_enable(struct intel_display *display,
 			  struct i915_power_well *power_well)
 {
-	enum phy phy = icl_aux_pw_to_phy(display, power_well);
-
-	if (intel_phy_is_tc(display, phy))
+	if (icl_aux_pw_is_tc_phy(display, power_well))
 		return icl_tc_phy_aux_power_well_enable(display, power_well);
 	else if (display->platform.icelake)
 		return icl_combo_phy_aux_power_well_enable(display,
@@ -584,9 +599,7 @@ static void
 icl_aux_power_well_disable(struct intel_display *display,
 			   struct i915_power_well *power_well)
 {
-	enum phy phy = icl_aux_pw_to_phy(display, power_well);
-
-	if (intel_phy_is_tc(display, phy))
+	if (icl_aux_pw_is_tc_phy(display, power_well))
 		return hsw_power_well_disable(display, power_well);
 	else if (display->platform.icelake)
 		return icl_combo_phy_aux_power_well_disable(display,
@@ -1845,7 +1858,7 @@ static void xelpdp_aux_power_well_enable(struct intel_display *display,
 	enum aux_ch aux_ch = i915_power_well_instance(power_well)->xelpdp.aux_ch;
 	enum phy phy = icl_aux_pw_to_phy(display, power_well);
 
-	if (intel_phy_is_tc(display, phy))
+	if (icl_aux_pw_is_tc_phy(display, power_well))
 		icl_tc_port_assert_ref_held(display, power_well,
 					    aux_ch_to_digital_port(display, aux_ch));