Dell 5570 (Sierra) supported?

[Bjørn Mork]

Dan Williams <dcbw at redhat.com> writes:
> On Tue, 2014-11-25 at 20:03 +0100, Manuel Lauss wrote:
>> > On Tue, 2014-11-25 at 19:54 +0100, Manuel Lauss wrote:
>> >
>> >>            |    power state: 'low'

Ouch.  Now I remembered where I last heard about this modem...
http://ubuntuforums.org/showthread.php?t=2195299&p=12886034#post12886034

And it most likely does not have anything to do with the modem at all.
It is some Dell laptop rfkill feature we just don't know how to
enable/use.

>> Well, rfkill list shows only bluetooth and wlan (and nfc card reader).
>> wwan is enabled in BIOS; the dell airplane mode switch acpi device node
>> doesn't do anything (tried to poke all methods with acpi_call).
>
> One more thing to double-check: is the SIM slot under the battery, and
> if so is the battery inserted and correctly seated?  My laptop (an HP,
> not a dell) has some kind of BIOS interlock so that when the battery is
> removed (or poorly secured) it will rfkill the WWAN card automatically
> to prevent SIM hotswapping.

Smart :-)  Yes, that sounds like something to verify.

But the fact that there is no wwan switch in the "rfkill list" output is
really a strong indication that we lack support for the wwan switch in
the dell laptop driver (for this laptop variant - it obviously works for
older Dell laptops).

If this is correct, then it really isn't an MM or modem driver issue.
It's more a problem for the platform-driver-x86 at vger.kernel.org list.

You could use the extremely useful Sierra AT commands to verify that the
problem is in fact external to the modem:

1) switch the modem to QMI mode:
     # echo 1 > /sys/bus/usb/devices/1-10/bConfigurationValue

2) use a terminal application to talk to the AT command port (might be
   different from ttyUSB2):
     $ minicom /dev/ttyUSB2

3) Get the detailed low power status:
      AT!PCINFO


I dont' remember if that command is password protected or not.  If it
is, then you could try AT!ENTERCND="A710" first.  But Dell might have
changed that password from the default.


Bjørn