[sane-devel] Scanner failure when connected via USB3

[Olaf Meeuwissen]

Mike Cloaked writes:

> On Sun, Oct 26, 2014 at 4:28 PM, Mike Cloaked <mike.cloaked at gmail.com>
> wrote:
>
>> On Tue, Sep 23, 2014 at 11:57 PM, Olaf Meeuwissen <
>> olaf.meeuwissen at avasys.jp> wrote:
>>>
>>>   $ sudo modprobe usbmon
>>>   $ sudo wireshark
>>>
>>> and selecting the right USB bus to capture traffic on.  The `usbmon#`
>>> numbers match the bus numbers that `lsusb` outputs.
>
> I had a little time this morning available to test the scanner.  I am
> testing on a Lenovo Y510p laptop with usb3 ports. The laptop is running
> arch linux fully up to date  with kernel 3.17.1-1-ARCH.
>
> The relevant sane package versions are:
> [snip]
>
> I was following the guide at
> https://www.kernel.org/doc/Documentation/usb/usbmon.txt
>
> I found that the usbmon directory was already mounted:
> # ls /sys/kernel/debug/usb/usbmon/
> 0s  0u  1s  1t  1u  2s  2t  2u  3s  3t  3u  4s  4t  4u
>
> Checking which bus was used when the scanner was plugged in was bus 1 from
> the lsusb command.
>
> The after pulling the usb cable out I did
> # cat /sys/kernel/debug/usb/usbmon/1u >
> /home/mike/Documents/debugging/scanner/vuescan.mon.out
>
> and then re-inserted the scanner usb cable into the usb3 port, and started
> up vuescan.
>
> After doing a single scan I stopped the log and saved it.
>
> Then I did the same but using xsane from the GIMP - and it reliably crashed
> xsane, but it also zeroed out the usb monitor log file!  Eventually I was
> able to stop the monitor stream and save the file before xsane finished
> crashing, and whilst the scanner was still producing a continuous screaming
> noise, I safeguarded the file as xsane1.mon.out.
>
> Both these files are attached.  I have not tried to get wireshark to
> analyse the data as I am not sure how to do it.

The idea is that you start/stop capturing USB traffic with wireshark
rather than cat whatever is left in the /sys/kernel/debug/usb/usbmon/
files.  Wireshark will read off that and presents you with an easier to
digest view of what went on.

If you don't have a GUI on the machine with the scanner, you can use
tshark instead to save to file and view it elsewhere.  Read the manual
page for instructions.

> Are these two log files a help in getting some diagnostics?

Not unless you're a USB kernel buff, which I'm not ;-)

Hope this helps,
-- 
Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS CORPORATION
FSF Associate Member #1962               Help support software freedom
                 http://www.fsf.org/jf?referrer=1962