On 05/22/2013 12:27 PM, Alan Stern wrote:
On Wed, 22 May 2013, Joe Julian wrote:
On 05/21/2013 03:20 PM, Joe Julian wrote:
I have about 100 of these creditcard/check scanners that are dropping
events. I was able to find some overflows that I assume are probably
related to the problem, "usb 4-1: ctrl urb status -75 received".
Short of asking the vendor to fix their product or compiling a custom
kernel, are there any other options? Can the MaxPacketSize or the
buffer size be overridden somehow (/sys/bus/usb/devices... maybe)?
I have started a dialog with UIC (Uniform Industrial Corp) about a fix,
but I'm not very hopeful. Is there anything I can do to work around the
overflow?
Without knowing more (like where the overflows occur and what data was
expected), it is impossible to answer this question. A usbmon trace
would help.
I spent the day at one of our stores capturing data from a small handful
of customer loyalty cards I picked up for this purpose. I was able to
capture 2 bad scans.
If I'm reading this correctly, there's nothing wrong that could be
corrected from the linux side, could you confirm?
I think that overflow was a red herring as none occurred during the bad
scans.
The best example is the last scan of the Qdoba card that ends in "I"
(7th from the bottom).
The usbmon capture is at
http://joejulian.name/media/uploads/usbcapture.usbmon.gz
The expected scan data was successive scans of the following cards:
%B6277200522629830^^391200077861?[
%B6277200522629848^^391200017860?S
%B6277200522629855^^391200027724?S
%B6277200522629863^^391200055339?[
%B6277200522629871^^391200079146?\
%B6010565032591577^QDOBA/VALUELINK^25010004000060072408 ?@
%B6010565032591494^QDOBA/VALUELINK^25010004000060073301 ?C
%B6010565032591700^QDOBA/VALUELINK^25010004000060076767 ?L
%B6010565032591551^QDOBA/VALUELINK^25010004000060073264 ?I
%B6010565032591536^QDOBA/VALUELINK^25010004000060075630 ?K
%B6010565032591528^QDOBA/VALUELINK^25010004000060072347 ?F
%B6010565032591569^QDOBA/VALUELINK^25010004000060075724 ?E
%B6010565032591544^QDOBA/VALUELINK^25010004000060075630 ?N
%B6010565032591502^QDOBA/VALUELINK^25010004000060074630 ?M
%B6010565032591510^QDOBA/VALUELINK^25010004000060074982 ?H
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