On Friday, September 28, 2012 05:16 PM, Alan Stern wrote:
On Fri, 28 Sep 2012, [iso-8859-1] Lassi V��t�m�inen wrote:
Ok. How can I tell when this error is visible in the logs? Status field is -22?
If that is the error you are most worried about, then yes. There were
other errors (URBs still pending) that caused khubd to hang, but there
was no way to tell why they occurred.
I am really not sure which error I should be worried about, if not that
-22 ?
To be most helpful, you should provide both a dmesg log and a usbmon
trace taken at the same time, from a kernel with CONFIG_USB_DEBUG
enabled. First unplug all the USB devices, then do "dmesg -c
/dev/null", then plug in all the USB devices, then start the usbmon
trace, then run the test. After the failure occurs, collect the trace
and the entire dmesg output and post them.
The new usbmon log with kernel 3.6-rc7 is available here, with the dmesg
log as well (the dmesg log does not show much to me...):
https://bugs.launchpad.net/ubuntustudio/+bug/1035602/comments/3
https://bugs.launchpad.net/ubuntustudio/+bug/1035602/comments/4
Would it be better to take the usbmon trace from all buses (0u, right?).
I don't know; it depends on what the test is doing. Which USB devices
does it read from and which devices does it write to? Are there any
other unrelated USB devices attached (hint: it helps if there aren't).
My test case: I have an MAudio MobilePre USB soundcard plugged in, Jackd
is running, and I am playing back a track in Ardour.
Or which usbmon socket should I take the traces on?
The ones that get the errors you want to investigate. Unforunately the
error messages printed out by the snd-usb-audio driver aren't very
helpful; they don't say what device they relate to.
Okay, this is sort of a given. I was merely asking that is it of any use
to listen to all buses, or is it just to a single one; the one that
causes the errors.
The *t and *u files already are described in usbmon.txt. Adding a
description of the *s files would be a good idea; I am always ready to
review patches.
Hmm, so they *are* the mysterious things referred to as '1t' and '1u' in
usbmon.txt. For a first-time reader that is not obvious, so might be a
place for improvement.. I'll think about that. :)
-Lassi
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