Plan to replace the XMM GNSS AT command

[Aleksander Morgado]

Hey Quincy,

> The Intel wants to remove the AT commands uesd for GNSS in the plugins/xmm from release 1.9.990, including AT+XLCSLSR, AT+XLCSSLP, AT+XLSRSTOP, as the Intel do not want to put those AT commands in open license. And the Intel offer a more powerful synthetic AT command to replaces those AT commands.
> Is that possible to replace those AT commands with the synthetic one in ModemManager new release? If not, any practical advice?

My suggestion for this would be to probe during runtime whether the
new suggested command is available, and if it isn't, still use
+XLCSLSR and the other commands. This is, extend the logic with the
new commands, but keep the other ones as a fallback. If all new XMM
based devices use the new command, we would be fine and the old ones
wouldn't be used ever; but we would still keep them just in case.

The XLCSLSR command is not only used in ModemManager, just google for
"XLCSLSR" and you'll see lots of other places where the command is
used even before we started using it in MM; e.g.:
https://pypi.org/project/em73xx/
https://forum.sierrawireless.com/t/gps-data-em7345-on-linux/7629
https://forums.lenovo.com/t5/ThinkPad-X-Series-Laptops/X1-Carbon-20BS-How-to-enable-GPS-with-AT-commands/td-p/3437835
http://blog.mclemon.io/thinkpad-x250-sms-and-gps-via-python

Also, by using the commands Intel is not "putting those AT commands in
open license", ModemManager is just using the AT commands.

-- 
Aleksander
https://aleksander.es