[PATCH] option: Do not try to bind to ADB interfaces

[Romain Izard]

Some modems now use the Android Debug Bridge to provide a debugging
interface, and some phones can also export serial ports managed by the
"option" driver.

The ADB daemon running in userspace tries to use USB interfaces with
bDeviceClass=0xFF, bDeviceSubClass=0x42, bDeviceProtocol=1

Prevent the option driver from binding to those interfaces, as they
will not be serial ports.

This can fix issues like:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=781256

Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
---
 drivers/usb/serial/option.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index 664e61f16b6a..f98943a57ff0 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -1987,6 +1987,12 @@ static int option_probe(struct usb_serial *serial,
 	if (iface_desc->bInterfaceClass == USB_CLASS_MASS_STORAGE)
 		return -ENODEV;
 
+	/* Do not bind Android Debug Bridge interfaces */
+	if (iface_desc->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
+		iface_desc->bInterfaceSubClass == 0x42 &&
+		iface_desc->bInterfaceProtocol == 1)
+		return -ENODEV;
+
 	/*
 	 * Don't bind reserved interfaces (like network ones) which often have
 	 * the same class/subclass/protocol as the serial interfaces.  Look at
-- 
2.17.1