primary device changing from boot to boot

[Aleksander Morgado]

On Tue, Sep 5, 2017 at 9:40 PM, Tim Harvey <tharvey at gateworks.com> wrote:
> On Tue, Sep 5, 2017 at 9:56 AM, Pičugins Arsenijs <crimier at yandex.ru> wrote:
>> I don't know if it's going to help you with this issue, but if you can hardcode a path to the serial port somewhere, take a look in the "/dev/serial/by-id" directory - it has symlinks to /dev/tty* entries that correspond to hardware serial ports currently connected. Names of the symlinks are generated from some kind of hardware IDs, so should be the same, no matter the order of enumeration (unless your hardware doesn't expose an unique ID that udev, or whatever makes those symlinks, could use)
>>
>
> It is true that the symlinks in /dev/serial/by-id are constant but I
> don't know how to get nm to use them as nmcli is particularlly finiky
> about what is allowed for the 'ifname' param.
>

Somehow related, you can also apply fixed "names" to "modem objects"
(i.e. not just separate ports) based on e.g. physical device path
(/sys/devices...). See
https://sigquit.wordpress.com/2016/10/06/naming-devices-in-modemmanager/

This "name" may be used to reference the modem in mmcli calls, and is
also set in the "Device" property of the "Modem" interface. What I'm
not sure, though, is whether you can use this name to configure NM
settings associated to the device; this should probably be something
that we should make possible if it isn't already.

-- 
Aleksander
https://aleksander.es