Huawei ME909s-120 modem goes offline and disappears

[Aleksander Morgado]

Hey!

>
> One more question:
> I found the following in the Huawei doc. When you talk about primary/secondary port, are we actually talking about Modem port/Uart port? Are they exchangeable?
>
> ...
> The ME909s provides four ports to interact with its host:
>  MODEM port: simulated using USB, for AT command interaction and establishing data connection.
> Port name: HUAWEI Mobile Connect-3G Modem
>  PCUI port: simulated using USB, for AT command interaction only.
> Port name: HUAWEI Mobile Connect-3G PCUI Interface
>  UART port: physical serial port, for AT command interaction and establishing data connection.
>  ECM port: simulated using USB, for establishing communication connection. Port name: CDC Ethernet Control Model (ECM)
> The ME909s also provides a port for debugging:
>  DIAG port: simulated using USB, for DIAG (diagnostic) command interaction (mainly used to debug modules at present).

The current automatic setup detected by MM for the ports looks like this:
<debug> [1576225994.234810]
(/sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4) tty/ttyUSB1 at
(primary)
<debug> [1576225994.234835]
(/sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4) tty/ttyUSB3 at
(secondary)
<debug> [1576225994.234857]
(/sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4) tty/ttyUSB1
data (primary)

Which shows a couple of things:
 * We're not using any ECM port for data connection, even if the
module should have one? I don't see any such port exposed in your
logs. If we had a ECM port exposed by the huawei_cdc_ncm driver, we
would definitely use it for data connection instead of PPP. Does your
system have the huawei_cdc_nmc and cdc-wdm drivers installed?
 * This modem may require/support modeswitching, and it looks like
there may even be a MBIM mode for this device, not sure if with the
same firmware you have or not. Do you have the cdc_mbim driver
installed in your system? Do you have the "usb modeswitch" program
installed?
* The TTY port types chosen by MM are not based on any udev rule or
any AT command, because AT^GETPORTMODE didn't return any hint. We may
want to improve that, as that could explain why the data->control
recovery doesn't work as expected. Does the Huawei command reference
specify which port is which? E.g. is ttyUSB1 the modem port and
ttyUSB3 the pcui port?

Also, could you get the output of "lsusb -v -d 12d1:15c1" and
"usb-devices" and attach it here?

-- 
Aleksander
https://aleksander.es