[patch added to 3.12-stable] USB: option: fix Cinterion AHxx enumeration

[Jiri Slaby <jslaby@suse.cz>]

From: John Ernberg <john.ernberg@actia.se>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit 4152b387da81617c80cb2946b2d56e3958906b3e upstream.

In certain kernel configurations where the cdc_ether and option drivers
are compiled as modules there can occur a race condition in enumeration.
This causes the option driver to enumerate the ethernet(wwan) interface
as usb-serial interfaces.

usb-devices output for the modem:
T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  5 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=1e2d ProdID=0055 Rev=00.00
S:  Manufacturer=Cinterion
S:  Product=AHx
C:  #Ifs= 6 Cfg#= 1 Atr=e0 MxPwr=10mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
I:  If#= 4 Alt= 0 #EPs= 1 Cls=02(commc) Sub=06 Prot=00 Driver=cdc_ether
I:  If#= 5 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether

Signed-off-by: John Ernberg <john.ernberg@actia.se>
Fixes: 1941138e1c02 ("USB: added support for Cinterion's products...")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/usb/serial/option.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index d82cc9ef25ec..81f6a572f016 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -1695,7 +1695,7 @@ static const struct usb_device_id option_ids[] = {
 	{ USB_DEVICE(CINTERION_VENDOR_ID, CINTERION_PRODUCT_EU3_P) },
 	{ USB_DEVICE(CINTERION_VENDOR_ID, CINTERION_PRODUCT_PH8),
 		.driver_info = (kernel_ulong_t)&net_intf4_blacklist },
-	{ USB_DEVICE(CINTERION_VENDOR_ID, CINTERION_PRODUCT_AHXX) },
+	{ USB_DEVICE_INTERFACE_CLASS(CINTERION_VENDOR_ID, CINTERION_PRODUCT_AHXX, 0xff) },
 	{ USB_DEVICE(CINTERION_VENDOR_ID, CINTERION_PRODUCT_PLXX),
 		.driver_info = (kernel_ulong_t)&net_intf4_blacklist },
 	{ USB_DEVICE(CINTERION_VENDOR_ID, CINTERION_PRODUCT_HC28_MDM) }, 
-- 
2.7.1