drm/i915/icl: Set TC type to unknown in the disconnection flow

Otherwise it would be in a inconsistent state as port is disconnected
but with a valid tc type.

Also setting it to unknown will earlier return
icl_tc_phy_disconnect() for any future calls to
intel_digital_port_connected(), this way we don't need to check if
port is marked as safe everytime.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181030215750.28213-2-jose.souza@intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -5102,21 +5102,24 @@ static void icl_tc_phy_disconnect(struct drm_i915_private *dev_priv,
 				  struct intel_digital_port *dig_port)
 {
 	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
-	u32 val;
 
-	if (dig_port->tc_type != TC_PORT_LEGACY &&
-	    dig_port->tc_type != TC_PORT_TYPEC)
+	if (dig_port->tc_type == TC_PORT_UNKNOWN)
 		return;
 
 	/*
-	 * This function may be called many times in a row without an HPD event
-	 * in between, so try to avoid the write when we can.
+	 * TBT disconnection flow is read the live status, what was done in
+	 * caller.
 	 */
+	if (dig_port->tc_type == TC_PORT_TYPEC ||
+	    dig_port->tc_type == TC_PORT_LEGACY) {
+		u32 val;
+
 		val = I915_READ(PORT_TX_DFLEXDPCSSS);
-	if (val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port)) {
 		val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
 		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
 	}
+
+	dig_port->tc_type = TC_PORT_UNKNOWN;
 }
 
 /*