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

From: Bastien Nocera <[email protected]>

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: <[email protected]> # 5.8
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Alan Stern <[email protected]>
Co-developed-by: M. Vefa Bicakci <[email protected]>
Tested-by: Bastien Nocera <[email protected]>
Signed-off-by: Bastien Nocera <[email protected]>
Signed-off-by: M. Vefa Bicakci <[email protected]>
Tested-by: Pan (Pany) YUAN <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 98b7449c11f3..4dfa44d6cc3c 100644
--- 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);