thunderbolt: Scan only valid NULL adapter ports in hotplug

The only way to expand Thunderbolt topology is through the NULL adapter
ports (typically ports 1, 2, 3 and 4). There is no point handling
Thunderbolt hotplug events on any other port.

Add a helper function (tb_port_is_null()) that can be used to determine
if the port is NULL port, and use it in software connection manager code
when hotplug event is handled.

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

2 files changed, 11 insertions, 4 deletions

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index cfc451c938fd..fb01396a62a9 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -356,10 +356,12 @@ static void tb_handle_hotplug(struct work_struct *work)
                 tb_port_info(port,
                              "got plug event for connected port, ignoring\n");
         } else {
-                tb_port_info(port, "hotplug: scanning\n");
-                tb_scan_port(port);
-                if (!port->remote)
-                        tb_port_info(port, "hotplug: no switch found\n");
+                if (tb_port_is_null(port)) {
+                        tb_port_info(port, "hotplug: scanning\n");
+                        tb_scan_port(port);
+                        if (!port->remote)
+                                tb_port_info(port, "hotplug: no switch found\n");
+                }
         }
 
 put_sw:
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 5b5ba8919086..260360ec59a9 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -350,6 +350,11 @@ static inline bool tb_port_has_remote(const struct tb_port *port)
         return true;
 }
 
+static inline bool tb_port_is_null(const struct tb_port *port)
+{
+        return port && port->port && port->config.type == TB_TYPE_PORT;
+}
+
 static inline bool tb_port_is_pcie_down(const struct tb_port *port)
 {
         return port && port->config.type == TB_TYPE_PCIE_DOWN;