[sane-devel] Xerox 3220 USB problem

[m. allan noah]

>> The usb problem with xerox_mfp was that `scanimage -L` shows the
>> xerox_mfp device only once, then it disappears. I need to replug the
>> USB in order to see it again, but this also means I cannot scan with
>> xerox_mfp. I can only reproduce this on a new laptop with usb 3.0
>> ports. Same kernel and SANE, old laptop -> no problem.
>>
>> There is no problem with smfp, aside from the speed.
>
> Ah. Thanks for exmplaining.
>
>> I can only reproduce this on a new laptop with usb 3.0
>
> xerox_mfp driver is also using internal sanei library for workign with
> usb. So problem may be there. (I don't know what smfp driver is using.)

Email threads of the past few weeks have made it clear that there is
some sort of USB 3 problem with sane-backends. Perhaps this would be a
good opportunity to investigate the problem- Could you get usbmon logs
of both drivers making identical scans. These two logs could be
compared to see why the vendor software is so slow, and might give us
a clue to fix the usb issue with sane backends, removing the need for
the vendor driver.

allan
-- 
"The truth is an offense, but not a sin"