With "nousb" cmdline booting, built-in serial drivers (ie. airecable) will trigger kernel oops. Indeed, if nousb, usb_serial_init will failed, and the usb serial bus type will not be registerd, then usb_serial_register call driver_register which try to register the driver to a not registered bus. Here add usb_disabled() check in usb_serial_register to fix it. Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx> --- drivers/usb/serial/usb-serial.c | 3 +++ 1 file changed, 3 insertions(+) diff -uprN a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c --- a/drivers/usb/serial/usb-serial.c 2009-02-14 18:17:16.111250634 +0800 +++ b/drivers/usb/serial/usb-serial.c 2009-02-14 18:19:42.809343462 +0800 @@ -1230,6 +1230,9 @@ int usb_serial_register(struct usb_seria /* must be called with BKL held */ int retval; + if (usb_disabled()) + return -ENODEV; + fixup_generic(driver); if (!driver->description) -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html