thunderbolt: Tear down existing tunnels when resuming from hibernate

If the boot firmware implements connection manager of its own it may not
create the paths in the same way or order we do. For example it may
create first PCIe tunnel and then USB3 tunnel. When we restore our
tunnels (first de-activating them) we may be doing that over completely
different tunnels and that leaves them possibly non-functional. For this
reason we re-use the tunnel discovery functionality and find out all the
existing tunnels, and tear them down. Once that is done we can restore
our tunnels.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 52 insertions, 16 deletions

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 2897a77d44c3..a231191b06c6 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -105,10 +105,11 @@ static void tb_remove_dp_resources(struct tb_switch *sw)
 	}
 }
 
-static void tb_discover_tunnels(struct tb_switch *sw)
+static void tb_switch_discover_tunnels(struct tb_switch *sw,
+				       struct list_head *list,
+				       bool alloc_hopids)
 {
 	struct tb *tb = sw->tb;
-	struct tb_cm *tcm = tb_priv(tb);
 	struct tb_port *port;
 
 	tb_switch_for_each_port(sw, port) {
@@ -116,24 +117,41 @@ static void tb_discover_tunnels(struct tb_switch *sw)
 
 		switch (port->config.type) {
 		case TB_TYPE_DP_HDMI_IN:
-			tunnel = tb_tunnel_discover_dp(tb, port);
+			tunnel = tb_tunnel_discover_dp(tb, port, alloc_hopids);
 			break;
 
 		case TB_TYPE_PCIE_DOWN:
-			tunnel = tb_tunnel_discover_pci(tb, port);
+			tunnel = tb_tunnel_discover_pci(tb, port, alloc_hopids);
 			break;
 
 		case TB_TYPE_USB3_DOWN:
-			tunnel = tb_tunnel_discover_usb3(tb, port);
+			tunnel = tb_tunnel_discover_usb3(tb, port, alloc_hopids);
 			break;
 
 		default:
 			break;
 		}
 
-		if (!tunnel)
-			continue;
+		if (tunnel)
+			list_add_tail(&tunnel->list, list);
+	}
 
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port)) {
+			tb_switch_discover_tunnels(port->remote->sw, list,
+						   alloc_hopids);
+		}
+	}
+}
+
+static void tb_discover_tunnels(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+
+	tb_switch_discover_tunnels(tb->root_switch, &tcm->tunnel_list, true);
+
+	list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
 		if (tb_tunnel_is_pci(tunnel)) {
 			struct tb_switch *parent = tunnel->dst_port->sw;
 
@@ -146,13 +164,6 @@ static void tb_discover_tunnels(struct tb_switch *sw)
 			pm_runtime_get_sync(&tunnel->src_port->sw->dev);
 			pm_runtime_get_sync(&tunnel->dst_port->sw->dev);
 		}
-
-		list_add_tail(&tunnel->list, &tcm->tunnel_list);
-	}
-
-	tb_switch_for_each_port(sw, port) {
-		if (tb_port_has_remote(port))
-			tb_discover_tunnels(port->remote->sw);
 	}
 }
 
@@ -1369,7 +1380,7 @@ static int tb_start(struct tb *tb)
 	/* Full scan to discover devices added before the driver was loaded. */
 	tb_scan_switch(tb->root_switch);
 	/* Find out tunnels created by the boot firmware */
-	tb_discover_tunnels(tb->root_switch);
+	tb_discover_tunnels(tb);
 	/*
 	 * If the boot firmware did not create USB 3.x tunnels create them
 	 * now for the whole topology.
@@ -1429,6 +1440,8 @@ static int tb_resume_noirq(struct tb *tb)
 {
 	struct tb_cm *tcm = tb_priv(tb);
 	struct tb_tunnel *tunnel, *n;
+	unsigned int usb3_delay = 0;
+	LIST_HEAD(tunnels);
 
 	tb_dbg(tb, "resuming...\n");
 
@@ -1439,8 +1452,31 @@ static int tb_resume_noirq(struct tb *tb)
 	tb_free_invalid_tunnels(tb);
 	tb_free_unplugged_children(tb->root_switch);
 	tb_restore_children(tb->root_switch);
-	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
+
+	/*
+	 * If we get here from suspend to disk the boot firmware or the
+	 * restore kernel might have created tunnels of its own. Since
+	 * we cannot be sure they are usable for us we find and tear
+	 * them down.
+	 */
+	tb_switch_discover_tunnels(tb->root_switch, &tunnels, false);
+	list_for_each_entry_safe_reverse(tunnel, n, &tunnels, list) {
+		if (tb_tunnel_is_usb3(tunnel))
+			usb3_delay = 500;
+		tb_tunnel_deactivate(tunnel);
+		tb_tunnel_free(tunnel);
+	}
+
+	/* Re-create our tunnels now */
+	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
+		/* USB3 requires delay before it can be re-activated */
+		if (tb_tunnel_is_usb3(tunnel)) {
+			msleep(usb3_delay);
+			/* Only need to do it once */
+			usb3_delay = 0;
+		}
 		tb_tunnel_restart(tunnel);
+	}
 	if (!list_empty(&tcm->tunnel_list)) {
 		/*
 		 * the pcie links need some time to get going.