Blacklisting certain functions on a USB device in udev?

[Justin Schoeman <justin@expertron.co.za>]

Hi all,

I am trying to get my Huawei E220 3G modem working with the new Linux 
kernels.

The USB device registers 3 functions. 2 usb-serial devices, and 1 
usb-storage device.  Unfortunately, a firmware bug is causing the device 
to reset when userland apps try to mount the usb-storage device.

A simple way to get things working is to just kill udevd after the 
serial ports are registered, and before the scsi device scan completes, 
but obviously this is not ideal ;-) .

I have been experimenting by creating /etc/udev/rules.d/01-blacklist, 
and adding rules to try ignore the storage device.

This:
SUBSYSTEMS="usb", ATTRS{idVendor}="12d1", OPTIONS:="ignore_device"

successfully ignores the USB device entirely (serial and storage options).

This:
SUBSYSTEMS="usb", ATTRS{idVendor}="12d1", 
ATTRS{bInterfaceClass}="08", OPTIONS:="ignore_device"

should only match the storage device, and ignore it, but it doesn't seem 
to work.

I have tried more exotic solutions like:
SUBSYSTEM="usb-serial", ATTRS{idVendor}="12d1", 
GOTO="blacklist_skip_huawei"
SUBSYSTEMS="usb", ATTRS{idVendor}="12d1", OPTIONS:="ignore_device"
LABEL="blacklist_skip_huawei"


but the storage device is still mounted.

Is there any way to debug the rule parsing to see exactly which rules 
are matched/violated?

Can anybody perhaps help with tips/advice on how to construct this 
blacklist?

Thanks,
Justin

PS I am not subscribed to the list.  Please CC me any replies.