thunderbolt: Fix nontrivial endpoint devices.

Fix issues observed with the Startech docking station:

Fix the type of the route parameter in tb_ctl_rx. It should be u64 and not
u8 (which only worked for short routes).

A thunderbolt cable contains two lanes. If both endpoints support it a
connection will be established on both lanes. Previously we tried to
scan below both "dual link ports". Use the information extracted from
the drom to only scan behind ports with lane_nr == 0.

Endpoints with more complex thunderbolt controllers have some of their
ports disabled (for example the NHI port or one of the HDMI/DP ports).
Accessing them results in an error so we now ignore ports which are
marked as disabled in the drom.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/thunderbolt/ctl.c

@@ -439,7 +439,7 @@ static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
  */
 static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer,
 				      size_t length, int timeout_msec,
-				      u8 route, enum tb_cfg_pkg_type type)
+				      u64 route, enum tb_cfg_pkg_type type)
 {
 	struct tb_cfg_result res;
 	struct ctl_pkg *pkg;

drivers/thunderbolt/switch.c

@@ -180,20 +180,17 @@ int tb_port_clear_counter(struct tb_port *port, int counter)
  *
  * Return: Returns 0 on success or an error code on failure.
  */
-static int tb_init_port(struct tb_switch *sw, u8 port_nr)
+static int tb_init_port(struct tb_port *port)
 {
 	int res;
 	int cap;
-	struct tb_port *port = &sw->ports[port_nr];
-	port->sw = sw;
-	port->port = port_nr;
-	port->remote = NULL;
+
 	res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
 	if (res)
 		return res;
 
 	/* Port 0 is the switch itself and has no PHY. */
-	if (port->config.type == TB_TYPE_PORT && port_nr != 0) {
+	if (port->config.type == TB_TYPE_PORT && port->port != 0) {
 		cap = tb_find_cap(port, TB_CFG_PORT, TB_CAP_PHY);
 
 		if (cap > 0)
@@ -202,7 +199,7 @@ static int tb_init_port(struct tb_switch *sw, u8 port_nr)
 			tb_port_WARN(port, "non switch port without a PHY\n");
 	}
 
-	tb_dump_port(sw->tb, &port->config);
+	tb_dump_port(port->sw->tb, &port->config);
 
 	/* TODO: Read dual link port, DP port and more from EEPROM. */
 	return 0;
@@ -329,6 +326,7 @@ void tb_switch_free(struct tb_switch *sw)
 		tb_plug_events_active(sw, false);
 
 	kfree(sw->ports);
+	kfree(sw->drom);
 	kfree(sw);
 }
 
@@ -381,18 +379,16 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
 
 	/* initialize ports */
 	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
-	GFP_KERNEL);
+				GFP_KERNEL);
 	if (!sw->ports)
 		goto err;
 
 	for (i = 0; i <= sw->config.max_port_number; i++) {
-		if (tb_init_port(sw, i))
-			goto err;
-		/* TODO: check if port is disabled (EEPROM) */
+		/* minimum setup for tb_find_cap and tb_drom_read to work */
+		sw->ports[i].sw = sw;
+		sw->ports[i].port = i;
 	}
 
-	/* TODO: I2C, IECS, EEPROM, link controller */
-
 	cap = tb_find_cap(&sw->ports[0], TB_CFG_SWITCH, TB_CAP_PLUG_EVENTS);
 	if (cap < 0) {
 		tb_sw_warn(sw, "cannot find TB_CAP_PLUG_EVENTS aborting\n");
@@ -400,10 +396,21 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
 	}
 	sw->cap_plug_events = cap;
 
-	if (tb_drom_read_uid_only(sw, &sw->uid))
-		tb_sw_warn(sw, "could not read uid from eeprom\n");
-	else
-		tb_sw_info(sw, "uid: %#llx\n", sw->uid);
+	/* read drom */
+	if (tb_drom_read(sw))
+		tb_sw_warn(sw, "tb_eeprom_read_rom failed, continuing\n");
+	tb_sw_info(sw, "uid: %#llx\n", sw->uid);
+
+	for (i = 0; i <= sw->config.max_port_number; i++) {
+		if (sw->ports[i].disabled) {
+			tb_port_info(&sw->ports[i], "disabled by eeprom\n");
+			continue;
+		}
+		if (tb_init_port(&sw->ports[i]))
+			goto err;
+	}
+
+	/* TODO: I2C, IECS, link controller */
 
 	if (tb_plug_events_active(sw, true))
 		goto err;
@@ -411,6 +418,7 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
 	return sw;
 err:
 	kfree(sw->ports);
+	kfree(sw->drom);
 	kfree(sw);
 	return NULL;
 }

drivers/thunderbolt/tb.c

@@ -38,6 +38,11 @@ static void tb_scan_port(struct tb_port *port)
 		return;
 	if (port->config.type != TB_TYPE_PORT)
 		return;
+	if (port->dual_link_port && port->link_nr)
+		return; /*
+			 * Downstream switch is reachable through two ports.
+			 * Only scan on the primary port (link_nr == 0).
+			 */
 	if (tb_wait_for_port(port, false) <= 0)
 		return;
 	if (port->remote) {