[sane-devel] R: Re: R: Re: R: Re: scanner Epson DX4250 not working in Ubuntu 11.10

[Giorgio F. Signorini]

 > From:  Richard Ryniker <ryniker at alum.mit.edu>
 > Date: Thu, 26 Apr 2012 08:02:03 -0400
 > 
 > >Now it is guess work why the device is temporarily unavailable when
 > >trying to reset it, but replies just fine to the status query to comes
 > >immediately after.
 > 
 > Timing issue?  Perhaps the two bytes written to the device start some
 > action that has not completed before the read request is tried,
 > therefore the "Resource temporarily unavailable" status.  If the read
 > operation is retried, it might succeed.

Would this explain why the backend works the first time it is called
from within a shell, and then stops working until a new shell is
opened (as I described earlier)?

 > If there are other devices on the same bus, activity that involves one of
 > those devices may be an issue

The EPSON is the only device on the USB bus.

-- Giorgio
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 Dr. Giorgio F. SIGNORINI, PhD    
 Dipartimento di Chimica           tel: +39-055-457-3085
 Universita` di Firenze         
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