Problems with ethtool and ttyUSB2

I am using a beaglebone black which has Debian 11, kernel 5.10 .168-ti-r71. I also have a GSM Modem connected to it, SIM7000E. I am trying to do a PPP connection. Weeks ago when I tried it I had no problem with it. Today that I want to try again I see a weird problem in syslog file.

Feb 28 09:06:28 BeagleBone kernel: [ 416.877062] musb-hdrc musb-hdrc.1: Babble

Feb 28 09:06:28 BeagleBone kernel: [ 416.881245] musb-hdrc musb-hdrc.1: VBUS_ERROR in a_wait_bcon (89, <AValid), retry #1, port1 00010100

Feb 28 09:06:28 BeagleBone kernel: [ 416.881255] musb-hdrc musb-hdrc.1: Babble

Feb 28 09:06:28 BeagleBone kernel: [ 416.885854] usb 1-1: USB disconnect, device number 3

Feb 28 09:06:28 BeagleBone kernel: [ 416.886719] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0

Feb 28 09:06:28 BeagleBone kernel: [ 416.886831] option 1-1:1.0: device disconnected

Feb 28 09:06:28 BeagleBone kernel: [ 416.893381] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1

Feb 28 09:06:28 BeagleBone kernel: [ 416.893524] option 1-1:1.1: device disconnected

Feb 28 09:06:28 BeagleBone kernel: [ 416.903030] option1 ttyUSB2: GSM modem (1-port) converter now disconnected from ttyUSB2

Feb 28 09:06:28 BeagleBone kernel: [ 416.903144] option 1-1:1.2: device disconnected

Feb 28 09:06:28 BeagleBone kernel: [ 416.904638] option1 ttyUSB3: GSM modem (1-port) converter now disconnected from ttyUSB3

Feb 28 09:06:28 BeagleBone kernel: [ 416.904765] option 1-1:1.3: device disconnected

Feb 28 09:06:28 BeagleBone kernel: [ 416.909438] option1 ttyUSB4: GSM modem (1-port) converter now disconnected from ttyUSB4

Feb 28 09:06:28 BeagleBone kernel: [ 416.909583] option 1-1:1.4: device disconnected

Feb 28 09:06:28 BeagleBone kernel: [ 416.910033] qmi_wwan 1-1:1.5 wwan0: unregister ‘qmi_wwan’ usb-musb-hdrc.1-1, WWAN/QMI device

Feb 28 09:06:34 BeagleBone kernel: [ 422.193485] usb 1-1: new high-speed USB device number 4 using musb-hdrc

Feb 28 09:06:34 BeagleBone kernel: [ 422.345237] usb 1-1: New USB device found, idVendor=1e0e, idProduct=9001, bcdDevice= 0.00

Feb 28 09:06:34 BeagleBone kernel: [ 422.345265] usb 1-1: New USB device strings: Mfr=3, Product=2, SerialNumber=4

Feb 28 09:06:34 BeagleBone kernel: [ 422.345275] usb 1-1: Product: SimTech SIM7000

Feb 28 09:06:34 BeagleBone kernel: [ 422.345284] usb 1-1: Manufacturer: SimTech, Incorporated

Feb 28 09:06:34 BeagleBone kernel: [ 422.345293] usb 1-1: SerialNumber: 1234567890ABCDEF

Feb 28 09:06:34 BeagleBone kernel: [ 422.358236] option 1-1:1.0: GSM modem (1-port) converter detected

Feb 28 09:06:34 BeagleBone kernel: [ 422.359020] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0

Feb 28 09:06:34 BeagleBone kernel: [ 422.359843] option 1-1:1.1: GSM modem (1-port) converter detected

Feb 28 09:06:34 BeagleBone kernel: [ 422.362388] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1

Feb 28 09:06:34 BeagleBone kernel: [ 422.363401] option 1-1:1.2: GSM modem (1-port) converter detected

Feb 28 09:06:34 BeagleBone kernel: [ 422.373416] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2

Feb 28 09:06:34 BeagleBone kernel: [ 422.374494] option 1-1:1.3: GSM modem (1-port) converter detected

Feb 28 09:06:34 BeagleBone kernel: [ 422.375296] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB3

Feb 28 09:06:34 BeagleBone kernel: [ 422.376173] option 1-1:1.4: GSM modem (1-port) converter detected

Feb 28 09:06:34 BeagleBone kernel: [ 422.378195] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB4

Feb 28 09:06:34 BeagleBone kernel: [ 422.386130] qmi_wwan 1-1:1.5: cdc-wdm0: USB WDM device

Feb 28 09:06:34 BeagleBone kernel: [ 422.397844] qmi_wwan 1-1:1.5 wwan0: register ‘qmi_wwan’ at usb-musb-hdrc.1-1, WWAN/QMI device, 06:8e:b>

Feb 28 09:06:35 BeagleBone systemd-udevd[1425]: Using default interface naming scheme ‘v247’.

Feb 28 09:06:35 BeagleBone systemd-udevd[1425]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.

If I open minicom at ttyUSB2 (which is the port that the modem uses for AT commands), I can communicate with the modem, but when I enter the pin for the SIM card, the minicom will stuck and say something like

Cannot open /dev/ttyUSB2!

I also tried it with another modem SIM7600E and has the same problem as the above. I rebooted the system, powered on/off, checked the power supply and still nothing works. I have no ethtool installed in the system. Any ideas for the above problems and how to solve them?

I don’t have your GSM modem, however, from the log file it appears your driver is broken.

Did you up date the kernel after the time it was known working?

No I didn’t update anything. The only thing I tried was to experiment with PRUs. Now I used a new beaglebone and it worked fine. I didn’t have problems anymore. Thank you for the reply.