Sun Nov 9 12:21:09 EST 2014


zoo:/home/tom# mount -t debugfs none_debugs /sys/kernel/debug
zoo:/home/tom# modprobe usbmon
zoo:/home/tom# ls /sys/kernel/debug/usb/usbmon
0s  0u  1s  1t  1u  2s  2t  2u  3s  3t  3u  4s  4t  4u

cat /sys/kernel/debug/usb/usbmon/0u |grep :1:026

Note that [1] says:

    The length of collected data is limited and can be less than the
    data length reported in the Data Length word.

I've seen this for packet lengths of 128 where only 8 words (32 bytes)
are presented.

[1] https://www.kernel.org/doc/Documentation/usb/usbmon.txt