Re: HUWAEI E1750 NDISDUP

[poma <pomidorabelisima gmail com>]

On 18.12.2013 18:57, Dan Williams wrote:
> On Wed, 2013-12-18 at 18:38 +0100, poma wrote:
> > On 18.12.2013 00:26, Dan Williams wrote:
> > > On Tue, 2013-12-17 at 23:50 +0100, poma wrote:
> > > > HUWAEI E1750 NDISDUP
> > >
> > > Is the difference between the two modes just the usb_modeswitch
> > > commands?  I see they have different USB IDs between first and second
> > > runs.
> >
> > USB Modeswitch has nothing to do with it, besides it doesn't work. ;)
> > Actually the device switches mode by itself. ;) 'pid 140c' is inherited
> > through a warm state(reboot) from proprietary OS. However if the device
> > is replugged(cold state) within the Linux kernel, it switches to the
> > 'pid 1436' mode.
> > And vice versa.
>
> That's still usb_modeswitch.  Windows is sending a specific message to
> the Huawei device telling to use a specific mode, and it switches to
> that mode.  After reboot to Linux, it's still in that mode.  But if you
> coldplug the device while in Linux, usb_modeswitch sends a message to
> the device that is different than what Windows sends.
>
> On Linux with ModemManager, we would prefer to use the "Windows" mode
> since that is more capable.  Unfortunately, usb_modeswitch needs changes
> to send the correct message to switch to the "Windows" mode too.
>
> All that said, if possible ModemManager should try to support the
> non-Windows cdc-ether mode too, but there may be bugs with that.

It's not up to you, it's really up to the HUWAEI folks to be more
involved in these issues.
Besides I would rather call it the "Firmware Modeswitch",
i.e. 'AT^U2DIAG=276' - the default device state, 12d1:1436 ;)


poma