Configuring a Conexant USB modem

[Jeffrey Walton]

Hi Everyone,

I'm having trouble using a USB modem. It is a Conexant modem but it is
not responding to AT commands. Sample code is at
https://pastebin.com/84YUn9ey .

I think the first thing I need to do is verify the kernel
configuration for the device. For that:

    $ sudo setserial -a /dev/ttyACM0
    /dev/ttyACM0, Line 0, UART: unknown, Port: 0x0000, IRQ: 0
        Baud_base: 115200, close_delay: 12, divisor: 0
        closing_wait: 750
        Flags: spd_normal

At this point I think I need to read some kernel docs. I'm not sure if
I should be in https://www.kernel.org/doc/Documentation/serial or
https://www.kernel.org/doc/Documentation/usb . Looking through the
pages nothing jumps out as specific to the Conexant.

Can someone suggest what my next steps are to verify the modem's
configuration with respect to the kernel and driver?

Thanks in advance.