[PATCH v3 19/47] thunderbolt: No need to transition the link to symmetric during suspend

[Imre Deak]

From: Mika Westerberg <mika.westerberg at linux.intel.com>

There is no point transitioning the link back to symmetric when
suspending if it was asymmetric. The USB4 spec says the link should come
up as it was configured prior entering sleep so this saves unnecessary
link transitions.

Signed-off-by: Mika Westerberg <mika.westerberg at linux.intel.com>
---
 drivers/thunderbolt/tb.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 67741eeca2942..5680bcb0ca49a 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -1643,7 +1643,8 @@ static void tb_discover_tunnels(struct tb *tb)
 	}
 }
 
-static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
+static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel,
+					  bool suspending)
 {
 	struct tb_port *src_port, *dst_port;
 	struct tb *tb;
@@ -1667,10 +1668,12 @@ static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
 		 */
 		tb_switch_dealloc_dp_resource(src_port->sw, src_port);
 		/*
-		 * If bandwidth on a link is < asym_threshold
-		 * transition the link to symmetric.
+		 * If bandwidth on a link is < asym_threshold transition
+		 * the link to symmetric. But only if we are not
+		 * entering suspend.
 		 */
-		tb_configure_sym(tb, src_port, dst_port, true);
+		if (!suspending)
+			tb_configure_sym(tb, src_port, dst_port, true);
 		/* Now we can allow the domain to runtime suspend again */
 		pm_runtime_mark_last_busy(&dst_port->sw->dev);
 		pm_runtime_put_autosuspend(&dst_port->sw->dev);
@@ -1704,7 +1707,7 @@ static void tb_free_invalid_tunnels(struct tb *tb)
 
 	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
 		if (tb_tunnel_is_invalid(tunnel))
-			tb_deactivate_and_free_tunnel(tunnel);
+			tb_deactivate_and_free_tunnel(tunnel, false);
 	}
 }
 
@@ -1989,7 +1992,7 @@ static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)
 	}
 
 	tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, out);
-	tb_deactivate_and_free_tunnel(tunnel);
+	tb_deactivate_and_free_tunnel(tunnel, false);
 	list_del_init(&port->list);
 
 	/*
@@ -2032,7 +2035,7 @@ static void tb_disconnect_and_release_dp(struct tb *tb)
 	 */
 	list_for_each_entry_safe_reverse(tunnel, n, &tcm->tunnel_list, list) {
 		if (tb_tunnel_is_dp(tunnel))
-			tb_deactivate_and_free_tunnel(tunnel);
+			tb_deactivate_and_free_tunnel(tunnel, true);
 	}
 
 	while (!list_empty(&tcm->dp_resources)) {
@@ -2179,7 +2182,7 @@ static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd,
 
 		if (tb_tunnel_match_dma(tunnel, transmit_path, transmit_ring,
 					receive_path, receive_ring))
-			tb_deactivate_and_free_tunnel(tunnel);
+			tb_deactivate_and_free_tunnel(tunnel, false);
 	}
 
 	/*
-- 
2.39.2