usbcore: Check both id_table and match() when both available

From: Bastien Nocera <hadess@hadess.net>

When a USB device driver has both an id_table and a match() function, make
sure to check both to find a match, first matching the id_table, then
checking the match() function.

This makes it possible to have module autoloading done through the
id_table when devices are plugged in, before checking for further
device eligibility in the match() function.

Cc: <stable@vger.kernel.org> # 5.8
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Co-developed-by: M. Vefa Bicakci <m.v.b@runbox.com>
Tested-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>
Tested-by: Pan (Pany) YUAN <pany@fedoraproject.org>
Link: https://lore.kernel.org/r/20201022135521.375211-2-m.v.b@runbox.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 98b7449..4dfa44d 100644 (file)
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -839,6 +839,22 @@ const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
        return NULL;
 }
 
+bool usb_driver_applicable(struct usb_device *udev,
+                          struct usb_device_driver *udrv)
+{
+       if (udrv->id_table && udrv->match)
+               return usb_device_match_id(udev, udrv->id_table) != NULL &&
+                      udrv->match(udev);
+
+       if (udrv->id_table)
+               return usb_device_match_id(udev, udrv->id_table) != NULL;
+
+       if (udrv->match)
+               return udrv->match(udev);
+
+       return false;
+}
+
 static int usb_device_match(struct device *dev, struct device_driver *drv)
 {
        /* devices and interfaces are handled separately */
@@ -853,17 +869,14 @@ static int usb_device_match(struct device *dev, struct device_driver *drv)
                udev = to_usb_device(dev);
                udrv = to_usb_device_driver(drv);
 
-               if (udrv->id_table)
-                       return usb_device_match_id(udev, udrv->id_table) != NULL;
-
-               if (udrv->match)
-                       return udrv->match(udev);
-
                /* If the device driver under consideration does not have a
                 * id_table or a match function, then let the driver's probe
                 * function decide.
                 */
-               return 1;
+               if (!udrv->id_table && !udrv->match)
+                       return 1;
+
+               return usb_driver_applicable(udev, udrv);
 
        } else if (is_usb_interface(dev)) {
                struct usb_interface *intf;
@@ -941,8 +954,7 @@ static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
                return 0;
 
        udev = to_usb_device(dev);
-       if (usb_device_match_id(udev, new_udriver->id_table) == NULL &&
-           (!new_udriver->match || new_udriver->match(udev) == 0))
+       if (!usb_driver_applicable(udev, new_udriver))
                return 0;
 
        ret = device_reprobe(dev);

diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index 22c887f..26f9fb9 100644 (file)
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -205,9 +205,7 @@ static int __check_for_non_generic_match(struct device_driver *drv, void *data)
        udrv = to_usb_device_driver(drv);
        if (udrv == &usb_generic_driver)
                return 0;
-       if (usb_device_match_id(udev, udrv->id_table) != NULL)
-               return 1;
-       return (udrv->match && udrv->match(udev));
+       return usb_driver_applicable(udev, udrv);
 }
 
 static bool usb_generic_driver_match(struct usb_device *udev)

diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index c893f54..82538da 100644 (file)
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -74,6 +74,8 @@ extern int usb_match_device(struct usb_device *dev,
                            const struct usb_device_id *id);
 extern const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
                                const struct usb_device_id *id);
+extern bool usb_driver_applicable(struct usb_device *udev,
+                                 struct usb_device_driver *udrv);
 extern void usb_forced_unbind_intf(struct usb_interface *intf);
 extern void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev);