Re: SIM Card Detection Issue on Dual-SIM LTE Module

Hello Samuel,

Thank you for your response. Here's the current status:

    When I set up Ubuntu Linux on the same device and configured the necessary settings, everything works, including hot-swap for the SIM card. I don't actually need dual SIM functionality; I just need it to work with a single SIM. Unfortunately, I have to install OpenBSD on this hardware and bring the LTE interface up.

I've also applied the kernel modifications you suggested, but the result remains the same every time: "SIM not inserted PIN required."

Original state:
openbsd76# usbdevs -vv -a 3
addr 03: 2c7c:0620 Quectel, EM120R-GL 
        super speed, power 224 mA, config 1, rev 4.09, iSerial e40fc2ef
        driver: umsm0
        driver: umsm1
        driver: umsm2
        driver: umsm3

With umsm disabled:
openbsd76# usbdevs -a 3 -vv
addr 03: 2c7c:0620 Quectel, EM120R-GL
        super speed, power 224 mA, config 1, rev 4.09, iSerial e40fc2ef
        driver: umb0
        driver: ugen0

I even disabled ugen, but the result didn't change:
openbsd76# usbdevs -a 3 -vv
addr 03: 2c7c:0620 Quectel, EM120R-GL
        super speed, power 224 mA, config 1, rev 4.09, iSerial e40fc2ef
        driver: umb0

The only difference after disabling umsm is that I can no longer connect to the modem via cu:
openbsd76# cu -l /dev/cuaU0
cu: open("/dev/cuaU0"): Device not configured
openbsd76# cu -l /dev/cuaU1
 cu: open("/dev/cuaU1"): Device not configured
openbsd76# cu -l /dev/cuaU2
 cu: open("/dev/cuaU2"): Device not configured
openbsd76# cu -l /dev/cuaU3
 cu: open("/dev/cuaU3"): Device not configured

Is the dual SIM card issue a known limitation? Or could the source of this problem be that the Quectel EM120R-GL module lacks a manual page and is therefore not officially supported by OpenBSD?

On Mon, Oct 28, 2024 at 11:58 AM Samuel Jayden <samueljaydan1994@gmail.com> wrote:

Hello Barbaros,

Have you checked if this hardware is functioning without issues? It might be worth installing Linux to see if you can establish a GSM connection there.

Additionally, disabling umsm in the kernel could be another potential solution. I think it's worth a try. Here's what you'll need to do:
config -e -f /bsd
disable umsm
quit
reboot

I hope this works for you.

On Mon, Oct 28, 2024 at 3:33 AM Barbaros Bilek <barbarosblek@gmail.com> wrote:

Hi misc,

I'm encountering an issue with a Quectel EM120R-GL LTE module with dual SIM slots on OpenBSD. The system (ifconfig umb0) consistently displays the error "SIM not inserted, PIN required," despite attempts to set the APN, reboot, and bring the interface up. I'm 100% certain that the PIN is disabled.

Here are some key command outputs and troubleshooting steps: (// are my comments)

• AT+QSIMSTAT? → +QSIMSTAT: 0,0 // (SIM not detected)
• AT+CPIN? → +CME ERROR: 10 // (SIM not ready)
• AT+CIMI → +CME ERROR: // 3 (operation not allowed)
• AT+QSIMDET=1,1 → OK // (SIM detection enabled)
• AT+QSIMSEL=1 or AT+QSIMSEL=2 → ERROR // (cannot switch SIM slot)

I also tried the following configurations with reboots after each change, but neither resolved the issue:

• AT+QSIMDET=0,0 followed by reboot
• AT+QSIMDET=1,0 followed by reboot 
• The AT+QSIMDET=0,0 command disables SIM detection for both slots, meaning the module will not check for the presence of a SIM card in either slot. Conversely, the AT+QSIMDET=1,0 command enables detection for the first SIM slot while disabling it for the second, allowing the module to check only the first slot for a SIM card. Neither configuration, however, successfully resolves the issue.

In each case, AT+QSIMSTAT? consistently returns +QSIMSTAT: 0,0; showing that the SIM is not detected. It appears that OpenBSD cannot detect or manage SIM slots in this MBIM mode, and the umb driver might not fully support dual-SIM functionality in this context.

Has anyone else encountered a similar issue or found a workaround for managing dual-SIM LTE modules on OpenBSD?
Thanks in advance for any insights!

P.S. Some useful command outputs:
openbsd76# usbdevs -a 3 -vv
addr 03: 2c7c:0620 Quectel, EM120R-GL
              super speed, power 224 mA, config 1, rev 4.09, iSerial e40fc2ef
              driver: umsm0
              driver: umsm1
              driver: umsm2
              driver: umsm3

It would be beneficial to add the Quectel EM120R-GL to the man umb(4) page. Especially if we can resolve this dual SIM issue. I'm also prepared to provide any additional outputs you need and to perform further actions as required.

Also dmesg is attached via this email.
Thanks in advance.

--
Barbaros