• John Ernberg's avatar
    USB: option: fix Cinterion AHxx enumeration · 52e7a898
    John Ernberg authored
    commit 4152b387 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: default avatarJohn Ernberg <john.ernberg@actia.se>
    Fixes: 1941138e ("USB: added support for Cinterion's products...")
    Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
    Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
    52e7a898
option.c 110 KB