thunderbolt: Create multiple DisplayPort tunnels if there are more DP IN/OUT pairs

Currently we only create one DisplayPort tunnel even if there would be
more DP IN/OUT pairs available. Specifically this happens when a router
is unplugged and we check if a new DisplayPort tunnel can be created. To
cover this create tunnels as long as we find suitable DP IN/OUT pairs.
Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/tb.c

@@ -1284,18 +1284,13 @@ static struct tb_port *tb_find_dp_out(struct tb *tb, struct tb_port *in)
 	return NULL;
 }
 
-static void tb_tunnel_dp(struct tb *tb)
+static bool tb_tunnel_one_dp(struct tb *tb)
 {
 	int available_up, available_down, ret, link_nr;
 	struct tb_cm *tcm = tb_priv(tb);
 	struct tb_port *port, *in, *out;
 	struct tb_tunnel *tunnel;
 
-	if (!tb_acpi_may_tunnel_dp()) {
-		tb_dbg(tb, "DP tunneling disabled, not creating tunnel\n");
-		return;
-	}
-
 	/*
 	 * Find pair of inactive DP IN and DP OUT adapters and then
 	 * establish a DP tunnel between them.
@@ -1323,11 +1318,11 @@ static void tb_tunnel_dp(struct tb *tb)
 
 	if (!in) {
 		tb_dbg(tb, "no suitable DP IN adapter available, not tunneling\n");
-		return;
+		return false;
 	}
 	if (!out) {
 		tb_dbg(tb, "no suitable DP OUT adapter available, not tunneling\n");
-		return;
+		return false;
 	}
 
 	/*
@@ -1400,7 +1395,7 @@ static void tb_tunnel_dp(struct tb *tb)
 	 * TMU mode to HiFi for CL0s to work.
 	 */
 	tb_increase_tmu_accuracy(tunnel);
-	return;
+	return true;
 
 err_free:
 	tb_tunnel_free(tunnel);
@@ -1415,6 +1410,19 @@ static void tb_tunnel_dp(struct tb *tb)
 	pm_runtime_put_autosuspend(&out->sw->dev);
 	pm_runtime_mark_last_busy(&in->sw->dev);
 	pm_runtime_put_autosuspend(&in->sw->dev);
+
+	return false;
+}
+
+static void tb_tunnel_dp(struct tb *tb)
+{
+	if (!tb_acpi_may_tunnel_dp()) {
+		tb_dbg(tb, "DP tunneling disabled, not creating tunnel\n");
+		return;
+	}
+
+	while (tb_tunnel_one_dp(tb))
+		;
 }
 
 static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)