Sierra EM7455 not recognized

Bjørn Mork bjorn at
Sun Jun 26 14:09:25 UTC 2016

Tomek Mańko <jaennirin at> writes:

>> "rfkill list" gives you the list of supported hardware and software
> switches
>> and their current state.
> This is actually a funny thing I forgot to mention, but I do have a switch
> that's labelled as `tpacpi_wwan_sw: Wireless WAN` which starts out
> soft-blocked,
> but unblocking it does nothing - no messages show up in `dmesg` nor `lsusb`
> shows any new devices. It's kinds baffling how the rfkill is registered by
> the
> system but not the modem itself.

Yes, that is a bit unexpected.  I wonder if there could be a problem
here.  But then again, we haven't seen any such reports from anyone else
struggling with making the modem work in modern Lenovo laptops, so I
think it is unlikely.

>> make sure that there is no unknown devices showing up
> Neither `lsusb` nor `usb-devices` seem to show any unrecognised devices:

Yes, that list makes it clear that there is no modem connected to any of
the USB controllers.

>> or possibly 1199:9078 if in bootloader mode
> That makes me think, don't I have to set something up specifically to feed
> it
> firmware?

No, that is not necessary.  It comes with firmware in flash.  It will
only enter booloader mode when requested by the firmware upgrade
utility, or if anything is wrong with the installed firmware.


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