Re: wwanX vs usbX

[Bjørn Mork <bjorn mork no>]

Dan Williams <dcbw redhat com> writes:

> This is true.  It is ugly, and it's a constant battle to tag every new
> adapter as DEVTYPE=wwan, and we'll always be behind.  It's the same
> thing with udev rules, we'll always be behind.  Plus udev rules are
> project specific now, so it would also be ugly to have eg NetworkManager
> look at ModemManager-provided udev rules tags so that it knows to ignore
> a WWAN device when ModemManager is not running.
>
> On Windows people only install the drivers and software for *one*
> device, so this is never a problem.  When they buy a new WWAN device
> from the same vendor, the old software gets uninstalled and only the new
> drivers exist.

Yes, Microsoft discovered USB class drivers with Windows 8.  So they are
only 13 years behind Linux now :)

> I'm not really sure how to fix it...

Nor am I.  So I guess we'll have to stick with the current approach
until someone comes up with the brilliant solution to all this.

I'll prepare a patch for cdc_ncm telling it to consider Huawei (0x12d1)
NCM class (02/0d/00) devices as wwan then, similar to the Ericsson, Dell
and Toshiba rules.

But I really hate these exceptions in class drivers.  It would have been
nice if the USB-IF had anticipated the problem by allocating specific
protocol numbers for WWAN devices using the ECM/EEM/NCM classes.  Too
late for that now of course.  And given the track record of most Mobile
Broadband vendors, it would probably have been pointless unless
Microsoft forced them to use it.

Anyway, MBIM and Microsoft will probably solve this for us wrt future
devices.  Crossing fingers...


Bjørn