Hi everybody,
Something happens in my T77W968 modem, as a result, it is detected by the USB 3.0 controllers, but not USB 2.0.
On PC / Vmware, where it is convenient to switch port emulation) It looks like this:
usb 2.0 emulation mode:
dmesg
[ 2216.890741] usb 2-1: new high-speed USB device number 6 using ehci-pci
[ 2217.163576] usb 2-1: device descriptor read/64, error 18
[ 2217.547061] usb 2-1: device descriptor read/64, error 18
[ 2217.901630] usb 2-1: new high-speed USB device number 7 using ehci-pci
[ 2218.179057] usb 2-1: device descriptor read/64, error 18
[ 2218.575801] usb 2-1: device descriptor read/64, error 18
[ 2218.683654] usb usb2-port1: attempt power cycle
[ 2219.249190] usb 2-1: new high-speed USB device number 8 using ehci-pci
[ 2219.294695] usb 2-1: Invalid ep0 maxpacket: 9
[ 2219.556620] usb 2-1: new high-speed USB device number 9 using ehci-pci
[ 2219.601274] usb 2-1: Invalid ep0 maxpacket: 9
[ 2219.616137] usb usb2-port1: unable to enumerate USB device
usb 3.0 emulation mode:
dmesg
[ 1990.269559] usb 4-1: new SuperSpeed Gen 1 USB device number 3 using xhci_hcd
[ 1990.292143] usb 4-1: New USB device found, idVendor=1bc7, idProduct=1910, bcdDevice= 3.18
[ 1990.292145] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1990.292145] usb 4-1: Product: Telit LN960 Mobile Broadband
[ 1990.292146] usb 4-1: Manufacturer: Telit
[ 1990.292146] usb 4-1: SerialNumber: 0123456789ABCDEF
[ 1990.339521] cdc_mbim 4-1:2.0: cdc-wdm0: USB WDM device
[ 1990.339663] cdc_mbim 4-1:2.0 wwan0: register ‘cdc_mbim’ at usb-0000:03:00.0-1, CDC MBIM, 3e:c6:99:54:47:b3
Those, on a PC with USB 3.0 and Linux/Windows, the modem is functional and can be used.
The problem is that when it plugged into a router with openwrt and a USB 3.0 port, the modem is picked up by the USB 2.0 (xhci-mtk/2p, 480M) controller (dmesg is empty there, you can only guess what is in it) and as a result it is not detected and does not start, the lsusb command does not sees the device at all.
How to make the router pick it up with the USB 3.0 controller (xhci-mtk/1p, 5000M) first?
The options are:
- turn off support for usb 2.0 emulation in the router (how - hardware or software)? removing ehci packages did not help, hub-ctrl also does not work
- special cable between the modem and the usb port of the router, turning off the power / data lines usb 2.0 (which one?)
- change the priority of the connection to 3.0 / 2.0 (how?)
- something else?
root@openwrt:~# uname -a
Linux openwrt 4.14.221 #0 SMP Mon Feb 15 15:22:37 2021 mips GNU/Linux
root@openwrt:~# lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci-mtk/1p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci-mtk/2p, 480M
root@openwrt:~# opkg list-installed | grep usb
kmod-usb-core - 4.14.221-1
kmod-usb-ledtrig-usbport - 4.14.221-1
kmod-usb-net - 4.14.221-1
kmod-usb-net-cdc-ether - 4.14.221-1
kmod-usb-net-cdc-mbim - 4.14.221-1
kmod-usb-net-cdc-ncm - 4.14.221-1
kmod-usb-net-huawei-cdc-ncm - 4.14.221-1
kmod-usb-net-qmi-wwan - 4.14.221-1
kmod-usb-net-rndis - 4.14.221-1
kmod-usb-serial - 4.14.221-1
kmod-usb-serial-option - 4.14.221-1
kmod-usb-serial-wwan - 4.14.221-1
kmod-usb-storage - 4.14.221-1
kmod-usb-wdm - 4.14.221-1
kmod-usb3 - 4.14.221-1