EM9191 does not bring up the serial interface

[nkefgr]

Hi all,
i started testing an EM9191 with a compatible adapter. I am using the Ubuntu 20.04 lts with 5.11.0-27-generic kernel. The modem is recognized and brings up the cdc-mbim interface but not serial inteface (/dev/ttyUSBxx). I was able to connect successfully via mbim.
I know that is has to do with the USB composition mode or (and) maybe with the kernel version i am using does not configures correctly the device.
Unfortunately I cannot access the USBCOMP via the at commands to check the programmed value.

I am providing the kernel logs:

Code: Select all

[ 7075.385205] usb 2-6: new SuperSpeed Gen 1 USB device number 4 using xhci_hcd
[ 7075.406015] usb 2-6: config 1 has an invalid interface number: 4 but max is 3
[ 7075.406027] usb 2-6: config 1 has no interface number 2
[ 7075.406426] usb 2-6: New USB device found, idVendor=1199, idProduct=90d3, bcdDevice= 0.06
[ 7075.406435] usb 2-6: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 7075.406440] usb 2-6: Product: Sierra Wireless EM9191
[ 7075.406445] usb 2-6: Manufacturer: Sierra Wireless, Incorporated
[ 7075.406449] usb 2-6: SerialNumber: XXXXXXXXXXXX
[ 7075.437925] cdc_mbim 2-6:1.0: setting rx_max = 16384
[ 7075.438392] cdc_mbim 2-6:1.0: cdc-wdm1: USB WDM device
[ 7075.438732] cdc_mbim 2-6:1.0 wwan0: register 'cdc_mbim' at usb-0000:00:14.0-6, CDC MBIM, 26:5e:43:f6:8d:1c

cat /sys/kernel/debug/usb/devices

Code: Select all

T:  Bus=02 Lev=01 Prnt=01 Port=05 Cnt=01 Dev#=  4 Spd=5000 MxCh= 0
D:  Ver= 3.20 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 9 #Cfgs=  1
P:  Vendor=1199 ProdID=90d3 Rev= 0.06
S:  Manufacturer=Sierra Wireless, Incorporated
S:  Product=Sierra Wireless EM9191
S:  SerialNumber=XXXXXXXXXXXX
C:* #Ifs= 4 Cfg#= 1 Atr=a0 MxPwr=896mA
A:  FirstIf#= 0 IfCount= 2 Cls=02(comm.) Sub=0e Prot=00
I:* If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=0e Prot=00 Driver=cdc_mbim
E:  Ad=81(I) Atr=03(Int.) MxPS=  64 Ivl=32ms
I:  If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
I:* If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
E:  Ad=8e(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=0f(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E:  Ad=83(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=82(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=01(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=(none)
E:  Ad=84(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms

udevadm info -p /sys/bus/usb/devices/2-6

Code: Select all

P: /devices/pci0000:00/0000:00:14.0/usb2/2-6
N: bus/usb/002/004
L: 0
E: DEVPATH=/devices/pci0000:00/0000:00:14.0/usb2/2-6
E: DEVNAME=/dev/bus/usb/002/004
E: DEVTYPE=usb_device
E: DRIVER=usb
E: PRODUCT=1199/90d3/6
E: TYPE=0/0/0
E: BUSNUM=002
E: DEVNUM=004
E: MAJOR=189
E: MINOR=131
E: SUBSYSTEM=usb
E: USEC_INITIALIZED=7075664631
E: ID_VENDOR=Sierra_Wireless__Incorporated
E: ID_VENDOR_ENC=Sierra\x20Wireless\x2c\x20Incorporated
E: ID_VENDOR_ID=1199
E: ID_MODEL=Sierra_Wireless_EM9191
E: ID_MODEL_ENC=Sierra\x20Wireless\x20EM9191
E: ID_MODEL_ID=90d3
E: ID_REVISION=0006
E: ID_SERIAL=Sierra_Wireless__Incorporated_Sierra_Wireless_EM9191_8W1042018701A118
E: ID_SERIAL_SHORT=XXXXXXXXXXXX
E: ID_BUS=usb
E: ID_USB_INTERFACES=:020e00:0a0002:ff0000:ffff30:
E: ID_VENDOR_FROM_DATABASE=Sierra Wireless, Inc.
E: ID_PATH=pci-0000:00:14.0-usb-0:6
E: ID_PATH_TAG=pci-0000_00_14_0-usb-0_6

Until now I was lucky and my other modems worked out of the box so I have no experience configuring the USB composition mode (usb_modeswitch whatsoever), but any hints and information would be greatly appreciated.

Thanks in advance!
nkef

[Didneywhorl]

Which mode specifically are you wanting?

After entering

Code: Select all

AT!ENTERCND="A710"

I can access

Code: Select all

AT!USBCOMP?

But the EM919x modems only ship with MBIM mode, no QMI

Are you hoping for PCIe mode?

[nkefgr]

I want to use MBIM mode + serial interfaces (/dev/ttyUSBxx) , i cant sent AT commands for the moment.

[Didneywhorl]

Ohhhhhh!!!

Which adapter are you using?

[nkefgr]

Ohhhhhh!!!

Which adapter are you using?

I got one demo adapter board from a good Chinese manufacturer https://www.facebook.com/LTE-roter-1687936271740/, it will be available soon for sale.

I tested it also tested with Windows drivers, the modem only exposes the Serial Wireless DM port and not the AT serial port.
.
So I have to find a way to make the modem to expose the serial AT port , it has not to do with Windows or Linux.

[Didneywhorl]

That looks like a router, not an adapter, and that shows as a mini-pcie modem router. Maybe you linked the wrong item?

My adapter doesn't have this issue. I think the board you have isn't setting the modem into USB mode. It isn't a command, it's a pin voltage.

[nkefgr]

That looks like a router, not an adapter, and that shows as a mini-pcie modem router. Maybe you linked the wrong item?

My adapter doesn't have this issue. I think the board you have isn't setting the modem into USB mode. It isn't a command, it's a pin voltage.

These is the adapter https://fb.watch/7Pq3QpDEx/ m2 to usb-3

[nkefgr]

I also asked at the sierra wireless forum and a forum user gave a workaround for the issue !
It seems that the modem exposes the AT serial interface but the driver does not recognizes it.

Code: Select all

I:* If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=(none)
E:  Ad=84(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms

The workaround is to use the option driver

Code: Select all

modprobe option
echo 1199 90d3 >/sys/bus/usb-serial/drivers/option1/new_id

after that the serial interfaces are brought up!

Code: Select all

[   45.672459] usbcore: registered new interface driver usbserial_generic
[   45.672479] usbserial: USB Serial support registered for generic
[   45.677324] usbcore: registered new interface driver option
[   45.677334] usbserial: USB Serial support registered for GSM modem (1-port)
[   50.148315] option 2-5:1.3: GSM modem (1-port) converter detected
[   50.148648] usb 2-5: GSM modem (1-port) converter now attached to ttyUSB0
[   50.148781] option 2-5:1.4: GSM modem (1-port) converter detected
[   50.149007] usb 2-5: GSM modem (1-port) converter now attached to ttyUSB1

https://forum.sierrawireless.com/t/em91 ... on/24783/3

The only unexplained issue is why the windows driver does not bring up the AT serial interface.

[Didneywhorl]

Windows does odd things for me as well. I have to select the WWAN port of the Sierra to send AT commands. It doesn't echo to the terminal correctly, but it does work. I have to send the AT command, disconnect, reconnect, and then I receive the echo.

[Sixpack99]

The only unexplained issue is why the windows driver does not bring up the AT serial interface.

Did you ever figure out how to get the serial interface working in Windows?

[nkefgr]

The only unexplained issue is why the windows driver does not bring up the AT serial interface.

Did you ever figure out how to get the serial interface working in Windows?

Unfortunately no.

[nkefgr]

A note for people using any lte modem with custom lte connection scripts on casual Linux distributions. After upgrading my Ubuntu 20.04 suddenly I had all sort of issue with the at commend serial interface. Minicom hang during the session , output of at commands was truncated e.t.c. I got suspicious that some other process was using the AT command serial interface and then I found out that for no apparent reason ubuntu's modem-manager got enabled and started using the at command serial interface ...
I disabled the modem-manager and all was fine!