Is there support for modem with a single UART port ? (SIM5320A with usb disconnected)

[Aleksander Morgado]

Hey

>
> "Couldn't refresh signal quality: 'No AT port available to run command'"
>

The previous log message is expected once the TTY goes into connected mode.

> Can ModemManager work with a single physical UART port? any guide here?
>

Yes it can, you should not need any special setup to handle that, as
long as you have already sorted out e.g. baudrate settings and such.

> ModemManager[1133]: <debug> [1574094017.501539] (ttyAMA0): --> 'ATD*99***1#<CR>'
> ModemManager[1133]: <debug> [1574094017.520418] (ttyAMA0): <-- '<CR><LF>CONNEC'
> ModemManager[1133]: <debug> [1574094017.521287] (ttyAMA0): <-- 'T 115200'
> ModemManager[1133]: <debug> [1574094017.522064] (ttyAMA0): <-- '<CR><LF>'
> ModemManager[1133]: <debug> [1574094017.522990] (ttyAMA0): port now connected
> ModemManager[1133]: <debug> [1574094017.523252] Connected bearer '/org/freedesktop/ModemManager1/Bearer/0'
> ModemManager[1133]: <info>  [1574094017.524890] Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> connected)
> ModemManager[1133]: <info>  [1574094017.526928] Simple connect state (8/8): All done

All the previous logs look good up until the TTY gets in connected mode.

> ModemManager[1133]: <debug> [1574094017.528284] (ttyAMA0) device open count is 2 (close)
> ModemManager[1133]: <debug> [1574094022.884121] Couldn't load network timezone: No AT port available to run command
> ModemManager[1133]: <warn>  [1574094022.884301] Couldn't load network timezone from the current network
> ModemManager[1133]: <debug> [1574094047.903513] loading signal quality...
> ModemManager[1133]: <debug> [1574094047.904192] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094047.904316] Periodic signal quality checks scheduled in 30s
> ModemManager[1133]: <debug> [1574094047.905267] Connection monitoring is unsupported by the device
> ModemManager[1133]: <debug> [1574094077.908613] Signal quality value not updated in 60s, marking as not being recent
> ModemManager[1133]: <debug> [1574094077.909225] loading signal quality...
> ModemManager[1133]: <debug> [1574094077.912293] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094077.913112] Periodic signal quality checks scheduled in 30s
> ModemManager[1133]: <debug> [1574094107.909341] loading signal quality...
> ModemManager[1133]: <debug> [1574094107.910887] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094107.911877] Periodic signal quality checks scheduled in 30s
> ModemManager[1133]: <debug> [1574094137.909770] loading signal quality...
> ModemManager[1133]: <debug> [1574094137.910968] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094137.911119] Periodic signal quality checks scheduled in 30s
> ModemManager[1133]: <debug> [1574094167.909603] loading signal quality...
> ModemManager[1133]: <debug> [1574094167.910793] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094167.910940] Periodic signal quality checks scheduled in 30s
> ModemManager[1133]: <debug> [1574094197.909420] loading signal quality...
> ModemManager[1133]: <debug> [1574094197.910612] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094197.910761] Periodic signal quality checks scheduled in 30s
> ModemManager[1133]: <debug> [1574094227.908847] loading signal quality...
> ModemManager[1133]: <debug> [1574094227.910030] Couldn't refresh signal quality: 'No AT port available to run command'
> ModemManager[1133]: <debug> [1574094227.910179] Periodic signal quality checks scheduled in 30s
>

All previous logs are expected in MM because the TTY is now "owned" by
upper layers (e.g. NM, that should run pppd).

You need to debug further what happens at NetworkManager/pppd layer.
Is this issue being reported here the same as this one here?
https://gitlab.freedesktop.org/mobile-broadband/ModemManager/issues/157#note_300284

-- 
Aleksander
https://aleksander.es