Hey! > > I assume the "(tty/ttyUSB6) at port timed out 10 consecutive times" is a > real error, for unknown reasons. What's worrying me is how it is > handled. I do not expect the modem to disconnect and disappear from > ModemManager due to an error like this, which seems to be related to the > optional at port only. Giving up seems excessive. Restart is fine as a > last resort. Stop is not. >
The AT port is optional in a QMI/MBIM based modem only in the sense that it is not required for a data connection. Unfortunately, the AT port in a QMI/MBIM modem is *not* optional if you require some features that are only available via AT ports, e.g. thinking on the most critical one being Voice support. In your setup, you don't want to handle incoming calls, but there are other setups (e.g. the Librem5) where losing the AT port would mean a very very critical thing. The fact that MM ends up removing the modem and gives up is not ideal, I agree with that. For cases where the AT port is the control port, removing the modem from MM would trigger "upper layers" (e.g. a monitoring process that looks the MM interfaces in DBus) to e.g. cut power to the device completely (not in standard setups, though, this is more a custom hardware setup thing usually) and the give it power back, forcing a real full device reset. But, for cases where the AT port is not the control one, we could instead do something like trigger a full device reset using QMI/MBIM to see if we can recover the AT port in that case. That would be better than forgetting about the modem completely. But I understand that this may also be not ideal because you may not want voice support and you would prefer to just ignore the loss of the AT port and keep the modem connected... Anyway, as you also said, having lost the AT port may indicate other kinds of internal problems, so attempting to trigger a reset ourselves wouldn't be that bad in this case? I'm open to suggestions on how to best handle this. Until now ModemManager hasn't done too many control things "by itself", but I understand this may be one of those things that could be automatically handled. It wouldn't be a bad idea to start using a configuration file that would allow disabling these smarts if needed. -- Aleksander https://aleksander.es _______________________________________________ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
