greybus: interface: fix hot-unplug control-connection timeouts

Set an interface disconnected flag when the interface has been
hot-unplugged (e.g. forcibly removed or after a reboot), and use it to
disable the control connection early when deregistering the interface
and its bundles.

This avoids a one-second (default) timeout for every enabled connection
(e.g. one per bundle) at hot-unplug, something which for the default
gpbridge manifest currently amounts to five seconds.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/interface.c

@@ -130,6 +130,9 @@ void gb_interface_remove(struct gb_interface *intf)
 	struct gb_bundle *bundle;
 	struct gb_bundle *next;
 
+	if (intf->disconnected)
+		gb_control_disable(intf->control);
+
 	list_for_each_entry_safe(bundle, next, &intf->bundles, links)
 		gb_bundle_destroy(bundle);
 

drivers/staging/greybus/interface.h

@@ -35,6 +35,7 @@ struct gb_interface {
 
 	/* The interface needs to boot over unipro */
 	bool boot_over_unipro;
+	bool disconnected;
 };
 #define to_gb_interface(d) container_of(d, struct gb_interface, dev)
 

drivers/staging/greybus/svc.c

@@ -335,9 +335,10 @@ static int gb_svc_hello(struct gb_operation *op)
 static void gb_svc_intf_remove(struct gb_svc *svc, struct gb_interface *intf)
 {
 	u8 intf_id = intf->interface_id;
-	u8 device_id;
+	u8 device_id = intf->device_id;
+
+	intf->disconnected = true;
 
-	device_id = intf->device_id;
 	gb_interface_remove(intf);
 
 	/*