Re: [MM] Huawei E1820 and NDISDUP

[Dan Williams <dcbw redhat com>]

On Mon, 2013-06-03 at 21:31 +0000, Graham Inggs wrote:
> My Huawei E1820 works fine with ModemManager in PPP mode.
> I tried to get it to work with NDISDUP.  I added the following lines to 
> plugins/huawei/77-mm-huawei-net-port-types.rules:
>
> # Huawei E1820 firmware 11.831.03.00.00
> SUBSYSTEMS=="usb", ATTRS{bInterfaceClass}=="02", 
> ATTRS{bInterfaceSubClass}=="06",ATTRS{bInterfaceProtocol}=="ff", ENV{ID_MM_HUAWEI_NDISDUP_SUPPORTED}="1"
>
> ModemManager was then able to connect using the AT^NDISDUP command.
> I received an IP address and DNS settings, but I didn't seem to be getting any traffic over the connection.
>
> I noticed the following line in the output of dmesg:
>
> [13317.359566] cdc_ether 2-5:1.1 wwan0: CDC: unexpected notification 01!
>
> I searched for this error and came across the following post:
>
> http://linux.derkeiler.com/Newsgroups/comp.os.linux.hardware/2011-09/msg00042.html
>
> Sure enough, changing the MAC address of wwan0 to 00:01:02:03:04:05 solved the problem!
> I am using an Ubuntu 3.8 kernel.  The modem works fine with AT^NDISDUP in Windows.
> Is this a problem with the cdc_ether driver, or something that could be fixed in ModemManager?

Wow, that's awesome.  I think Bjorn might have some input here, but it
might include swearing.  Quick question, in Windows does the device have
the 00/1/2/3/4/5 hardware address?

This is something that should be fixed in the kernel, or via udev rules,
but it's not something that ModemManager should ever have to deal with.
It's a hardware bug, or really a stupid firmware that probably doesn't
follow the cdc_ether specification to communicate it's MAC address to
the host.  We might be able to put some workarounds in the kernel
drivers, otherwise we'll have to work around it in userspace with udev
rules I think.

Dan