MC7710 only ttyISB0 available

IoT Modules MC/EM Series
1

Hello,

I am using MC7710 under Linux Ubuntu 10.04 (2.6.32-26-generic).

From time to time I see the following strange behaviour, the modem seems to be available under lsusb:
Bus 001 Device 002: ID 1199:68a3 Sierra Wireless, Inc.

but only ttyUSB0 is available and not the rest of the interfaces.

I see the following in dmesg:

Jun 20 12:16:58 probe10-4 kernel: [ 7.245217] usbcore: registered new interface driver usbserial
Jun 20 12:16:58 probe10-4 kernel: [ 7.248493] USB Serial support registered for generic
Jun 20 12:16:58 probe10-4 kernel: [ 7.251286] usbcore: registered new interface driver usbserial_generic
Jun 20 12:16:58 probe10-4 kernel: [ 7.251307] usbserial: USB Serial Driver core
Jun 20 12:16:58 probe10-4 kernel: [ 7.474543] lp: driver loaded but no devices found
Jun 20 12:16:58 probe10-4 kernel: [ 7.520946] USB Serial support registered for Sierra USB modem
Jun 20 12:16:58 probe10-4 kernel: [ 7.523235] sierra 1-2:1.0: Sierra USB modem converter detected
Jun 20 12:16:58 probe10-4 kernel: [ 7.529115] usb 1-2: Sierra USB modem converter now attached to ttyUSB0
Jun 20 12:16:58 probe10-4 kernel: [ 7.530018] usbcore: registered new interface driver sierra
Jun 20 12:16:58 probe10-4 kernel: [ 7.530039] sierra: v.1.7.40:USB Driver for Sierra Wireless USB modems

As you see, there are no entries for the rest of the interfaces. This is really strange as the problem happens from time to time and not consistently. Maybe the modem is in some strange mode? Any ideas?

Thank you,
Stathis

2

Are you using latest FW version?
If not, please try to update it and see if any improvement.

http://developer.sierrawireless.com/Resources/Resources/AirPrime/Software/MC7710%20FW%203,-d-,5,-d-,24,-d-,0_DIP.aspx

Thx

3

Hello,

thanks for your suggestion. Upgrading to this firmware does not really solve the problem.

I now see errors such as:

[17034.553534] ehci_hcd 0000:00:0f.5: force halt; handhake d080c014 00004000 00000000 -> -110
[17034.556438] sierra ttyUSB3: sierra_submit_rx_urbs: submit intr urb failed: -110
[17034.581854] sierra ttyUSB3: sierra_write - usb_submit_urb(write bulk) failed with status = -108
[17045.279539] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279597] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279646] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279695] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279744] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279793] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279842] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108
[17045.279891] sierra ttyUSB3: sierra_submit_rx_urbs: submit urb failed: -108

after downloading big files. Any ideas?

Thank you.

4

This is very bad, and you probably won’t be able to use that USB host controller after this without reloading the ehci_hcd driver. But I believe the error is completely unrelated to the MC7710. It will probably happen with any USB device connected to this controller.

The typo in that error message makes it extremely easy to Google. Kind of a feature :smiley:
See e.g.spinics.net/lists/linux-usb/msg29708.html

(Alan Stern is the person who currently knows the Linux EHCI driver best)

EDIT: If possible, you should try with a more recent kernel than 2.6.32.