USB Newbie: Enumerating Devices

May 18, 2007 2 Replies

Hi Folks,



Whilst trying to enumerate a USB device, I receive the following error message in my output:



"usb_os_find_devices: Found 001 on 004" "error obtaining child information: Inappropriate ioctl for device"



All I would like to know is what this means. (if you need any information regarding my setup, please ask!).



Thank you, Gavin.



Gavin Brewer Junior Software Engineer Axicon Auto ID Ltd snipped-for-privacy@axicon.com



Axicon Auto ID Ltd. Church Road, Weston on the Green, Oxford, OX25 3QP, UK Tel: +44 (0)1869 351155 Fax: +44(0)1869 351205 Company Registration Number: 2003365. England and Wales

My guesses:

"Found 001 on 004": found device 001 on USB bus 004 (these numbers are

1-based) "Inappropriate ioctl for device": the device's driver rejects the ioctl. Use 'strace' to find out which.

You might find more useful info in your syslog.

Could be a problem with your descriptors. If you have a USB analyzer see if it hangs while passing a particular descriptor. Sounds like it's getting the initial address but failing further along the setup. Jack Peacock

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