Policy re. cellular USB modem mode switch

[Oliver Martin <oliver.martin@student.tuwien.ac.at>]

Hello,

trying to get my ZTE MF628 HSDPA modem to work left me wondering if
there is an established policy whether or not to include the "mode
switch" code most cellular USB modems need in the kernel or not.
Currently, the MF628 requires a userspace helper called usb_modeswitch
to be called [1] to change from mass storage mode to serial mode.
After, that it can be used with the usbserial driver or preferably,
after one adds the right vendor and product id, with the option driver.

The only other such device I know is the Huawei E220, which doesn't
require any userspace tools since 2.6.20. The usb_modeswitch website
lists quite a lot of devices as supported, do any other of them
*require* the use of this (or another) userspace tool? If so, is this
considered acceptable?

The main reason I'm asking this is to find out if I should try to put
the mode switch code in the kernel or not. In the meantime, I'll reply
to this message with a patch to add the vendor/product id of the MF628
to the option driver, which I guess is needed in any case.

Regards,
Oliver

[1] http://www.draisberghof.de/usb_modeswitch/
http://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?t=81