[sane-devel] R: Re: R: Re: R: Re: scanner Epson DX4250 not working in Ubuntu 11.10
Giorgio F. Signorini
giorgio.signorini at unifi.it
Fri Apr 27 20:10:24 UTC 2012
Maybe I should point out here that the same scanner (with the same USB
cable!) works well on my laptop: Ubuntu 10.10, with
Problems arise only with my desktop: Ubuntu 11.10, with
The same happens to other users
>From what you say I suspect that the problem might be in the USB
** ubuntu 10.10 **
libusb-0.1-4 -> 2:0.1.12-15ubuntu2
libusbmuxd1 -> 1.0.4-1
libusb-1.0-0 -> 2:1.0.8-2
** Ubuntu 11.10 **
libusb-0.1-4 -> 2:0.1.12-18
libusbmuxd1 -> 1.0.7-1ubuntu0.11.10.1
libusb-1.0-0 -> 2:1.0.8-4
Would it be useful/possible/advisable to downgrade these?
> From: Olaf Meeuwissen <olaf.meeuwissen at avasys.jp>
> Date: Fri, 27 Apr 2012 08:01:24 +0900
> Richard Ryniker <ryniker at alum.mit.edu> writes:
> >>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.
> The two bytes written to the device cause a reset. All that needs to be
> done is initializing a limited number of values in the firmware, nothing
> that takes a significant about of time.
> > If the read operation is retried, it might succeed.
> That's something the backend should be doing to begin with when this
> particular condition happens during USB I/O but the sanei_usb wrapper
> merely returns SANE_STATUS_IO_ERROR so there no way you can tell what
> went wrong. For all the backend knows the USB might have been pulled
> or the device could have been turned off.
> Hope this helps,
> Olaf Meeuwissen, LPIC-2 FLOSS Engineer -- AVASYS CORPORATION
> FSF Associate Member #1962 Help support software freedom
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