USB serial: add dynamic id support to usb-serial core

Thanks to Johannes Hölzl <johannes.hoelzl@gmx.de> for fixing a few
things and getting it all working properly.

This adds support for dynamic usb ids to the usb serial core.  The file
"new_id" will show up under the usb serial driver, not the usb driver
associated with the usb-serial driver (yeah, it can be a bit confusing
at first glance...)

This patch also modifies the USB core to allow the usb-serial core to
reuse much of the dynamic id logic.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Johannes Hölzl <johannes.hoelzl@gmx.de>

1 files changed, 36 insertions, 5 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 716f6806cc89..90beb5c50e59 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -596,6 +596,39 @@ static struct usb_serial * create_serial (struct usb_device *dev,
         return serial;
 }
 
+static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
+                                                    struct usb_serial_driver *drv)
+{
+        struct usb_dynid *dynid;
+
+        spin_lock(&drv->dynids.lock);
+        list_for_each_entry(dynid, &drv->dynids.list, node) {
+                if (usb_match_one_id(intf, &dynid->id)) {
+                        spin_unlock(&drv->dynids.lock);
+                        return &dynid->id;
+                }
+        }
+        spin_unlock(&drv->dynids.lock);
+        return NULL;
+}
+
+static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
+                                                struct usb_interface *intf)
+{
+        const struct usb_device_id *id;
+
+        id = usb_match_id(intf, drv->id_table);
+        if (id) {
+                dbg("static descriptor matches");
+                goto exit;
+        }
+        id = match_dynamic_id(intf, drv);
+        if (id)
+                dbg("dynamic descriptor matches");
+exit:
+        return id;
+}
+
 static struct usb_serial_driver *search_serial_device(struct usb_interface *iface)
 {
         struct list_head *p;
@@ -605,11 +638,9 @@ static struct usb_serial_driver *search_serial_device(struct usb_interface *ifac
         /* Check if the usb id matches a known device */
         list_for_each(p, &usb_serial_driver_list) {
                 t = list_entry(p, struct usb_serial_driver, driver_list);
-                id = usb_match_id(iface, t->id_table);
-                if (id != NULL) {
-                        dbg("descriptor matches");
+                id = get_iface_id(t, iface);
+                if (id)
                         return t;
-                }
         }
 
         return NULL;
@@ -661,7 +692,7 @@ int usb_serial_probe(struct usb_interface *interface,
                         return -EIO;
                 }
 
-                id = usb_match_id(interface, type->id_table);
+                id = get_iface_id(type, interface);
                 retval = type->probe(serial, id);
                 module_put(type->driver.owner);