[PATCH v4 23/36] thunderbolt: Scan only valid NULL adapter ports in hotplug

[Mika Westerberg <mika.westerberg@linux.intel.com>]

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>
---
 drivers/thunderbolt/tb.c | 10 ++++++----
 drivers/thunderbolt/tb.h |  5 +++++
 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;
-- 
2.20.1