Sierra Wireless EM7355

[Dan Williams]

On Tue, 2015-01-13 at 11:00 -0700, Erinn Looney-Triggs wrote:
> On Monday, January 12, 2015 11:54:00 AM Dan Williams wrote:
> > On Mon, 2014-07-28 at 08:19 -0700, Erinn Looney-Triggs wrote:
> > > On 07/17/2014 12:22 AM, Bjørn Mork wrote:
> > > > Erinn Looney-Triggs <erinn.looneytriggs at gmail.com> writes:
> > > >> No problem. Unfortunately I may have spoken too soon. When I doo
> > > >> a warm reboot from windows into linux the modem works, when I
> > > >> start the system cold the modem doesn't work. I am going to try a
> > > >> few other combinations of things just to verify, so I'll get back
> > > >> to you.
> > > >> 
> > > >> Reminds me of my first Gobi modem which needed gobi_loader, I
> > > >> thought we were past that point but maybe it still needs a
> > > >> firmware loaded? I hope I haven't been missing that point all
> > > >> along.
> > > > 
> > > > Loading a firmware should not be necessary, but maybe selecting
> > > > the correct one is?
> > > > 
> > > > The newer modules can support multiple operator configurations.
> > > > And possibly also multiple images? See the AT commands
> > > > AT!GOBIIMPREF? and AT!PRIID? referred to in this discussion:
> > > > https://forum.sierrawireless.com/viewtopic.php?f=117&t=8007
> > > > 
> > > > If this is the issue, then maybe the mmcli "--firmware-list" and
> > > > "--firmware-select=[Unique ID]" commands can help too?  I have no
> > > > clue as I don't have any module supporting more than a single
> > > > operator config AFAIK.
> > > > 
> > > > 
> > > > Bjørn
> > > 
> > > No problem at all. As long as y'all don't mind the slow responses
> > > here, as much as I would like this to be my only priority, well I have
> > > other things.
> > > 
> > > So the modem is even more odd than all that I have implied. If, after
> > > running the firmware update in windows, I warm reboot the system into
> > > Fedora, the modem will work. However, it only works that once, the
> > > firmware update needs to be run again in windows in order for the
> > > modem to work under linux again, and again only that once.
> > > 
> > > It doesn't appear that I have multiple firmwares:
> > > sudo mmcli --firmware-list -m 0
> > > error: modem has no firmware capabilities
> > > 
> > > So if any of this rings any bells or brings up any ideas let me know.
> > > Otherwise, I'll keep poking at it to see what I can see.
> > 
> > Erinn,
> > 
> > Any luck with this device in the past 6 months?  I think the issue may
> > be due to rfkill/airplane-mode issues and the laptop this device is in.
> > When the device doesn't work, use 'sudo minicom -D /dev/ttyUSBx' for
> > each of the /dev/ttyUSB0, /dev/ttyUSB1, etc until you find one that
> > replies to the command "at!pcinfo?".  Then you'll get output that looks
> > like this:
> > 
> > State: 1 (ONLINE)
> > LPM force flags - W_DISABLE:0, User:0, Temp:0, Volt:0
> > W_DISABLE: 0
> > Poweroff mode: 1
> > LPM Persistent: 0
> > 
> > except yours probably says "LOW_POWER_MODE" or something like that.
> > What do you get?  If it says "BIOS:1" or "W_DISABLE:1" then that means
> > rfkill is likely to blame, and the Linux kernel may not know how to
> > drive rfkill on your laptop.
> > 
> > Dan
> 
> No, not really. I have been following the conversation that has been going on 
> regarding this though. Interestingly my modem seems to be a bit more fickle 
> then the other fellows. I can't reliably warm boot from windows to linux and 
> have the modem work, it sometimes does, most of the time it doesn't. 
> 
> There are no /dev/ttyUSB* files on my system so I can't really give you insight 
> there. 
> 
> I can give this interesting little tidbit from dmesg: 
> thinkpad_acpi: rfkill switch tpacpi_wwan_sw: radio is unblocked
> 
> But that may or may not have any bearing on this. I'll continue to follow 
> along and try to help out any way I can.
> 
> This is a Fedora 21 system now, I believe when this started I was running 
> Fedora 20.

We think we've figured it out now (a custom command that the Sierra
drivers send to the device), so possibly a ModemManager update will make
the modem work under Linux automatically now.  Not sure when those
packages will hit Fedora, but at least we think we know what's going on
now.

Dan