drm/i915/xe2hpd: Properly disable power in port A

Xe2_HPD has a different value to power down port A.

BSpec: 65450
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240430172850.1881525-6-radhakrishna.sripada@intel.com

drivers/gpu/drm/i915/display/intel_cx0_phy.c

@@ -2900,17 +2900,28 @@ void intel_mtl_pll_enable(struct intel_encoder *encoder,
 		intel_cx0pll_enable(encoder, crtc_state);
 }
 
+static u8 cx0_power_control_disable_val(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+
+	if (intel_encoder_is_c10phy(encoder))
+		return CX0_P2PG_STATE_DISABLE;
+
+	if (IS_BATTLEMAGE(i915) && encoder->port == PORT_A)
+		return CX0_P2PG_STATE_DISABLE;
+
+	return CX0_P4PG_STATE_DISABLE;
+}
+
 static void intel_cx0pll_disable(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
 	enum phy phy = intel_encoder_to_phy(encoder);
-	bool is_c10 = intel_encoder_is_c10phy(encoder);
 	intel_wakeref_t wakeref = intel_cx0_phy_transaction_begin(encoder);
 
 	/* 1. Change owned PHY lane power to Disable state. */
 	intel_cx0_powerdown_change_sequence(encoder, INTEL_CX0_BOTH_LANES,
-					    is_c10 ? CX0_P2PG_STATE_DISABLE :
-					    CX0_P4PG_STATE_DISABLE);
+					    cx0_power_control_disable_val(encoder));
 
 	/*
 	 * 2. Follow the Display Voltage Frequency Switching Sequence Before