[sane-devel] Unstable scanning with Fujitsu fi-7160

[m. allan noah]

Again, check for kernel-level errors using dmesg.

On Wed, Jan 14, 2026 at 2:59 PM Simon Matter <simon.matter at invoca.ch> wrote:

> Everything changed, yes.
> The button daemon is a quite small program so I expected it to work also
> with the new system. I was wrong here and now I try to find out why it
> leaves the system in a state where access to the device is blocked.
>
> Simon
>
> > What changed? Just the sane-backends version, or anything else (hardware,
> > OS, etc)
> >
> > allan
> >
> > On Wed, Jan 14, 2026 at 2:32 PM Simon Matter <simon.matter at invoca.ch>
> > wrote:
> >
> >> I can confirm now that the problem is with the button daemon
> >> scanmonitord-sanebd only and not with scanimage.
> >>
> >> When I run "SANE_DEFAULT_DEVICE=fujitsu:fi-7160:42929
> >> scanmonitord-sanebd"
> >> several times in a terminal and terminate it with Ctrl+C, it will
> >> suddenly
> >> say "Open of device fujitsu:fi-7160:42929 failed: Invalid argument".
> >> While studying the code of scanmonitord-sanebd.c I'm failing to
> >> understand
> >> what could be wrong. This has worked fine with SANE backends 1.0.24 but
> >> something has changed here.
> >>
> >> If anyone has an idea what could be wrong, please let me know. I'm quite
> >> lost here.
> >>
> >> Thanks,
> >> Simon
> >>
> >> > I start to believe the problem is not in SANE itself but in the button
> >> > daemon we are using (see attachement).
> >> >
> >> > Our software is running the button daemon and waits for events, then
> >> > terminates the button daemon and does the appropriate scanimage job,
> >> and
> >> > then starts the button daemon again.
> >> >
> >> > The button daemon is a modified version of some daemon which was
> >> floating
> >> > around many years ago. It has worked well for the last 15 years or so.
> >> > Maybe there is some modification needed to make it work well with
> >> newer
> >> > SANE.
> >> >
> >> > If someone who knows SANE better than me would take a look at it, that
> >> > would be much appreciated.
> >> >
> >> > Thanks,
> >> > Simon
> >> >
> >> >> We need to isolate the problem if possible- I expect if you compile
> >> an
> >> >> older, known working sane-backends on your current computer, the
> >> problem
> >> >> will persist. That would indicate hardware or OS level issue.
> >> >>
> >> >> allan
> >> >>
> >> >> On Wed, Jan 14, 2026 at 9:35 AM Simon Matter via sane-devel <
> >> >> sane-devel at alioth-lists.debian.net> wrote:
> >> >>
> >> >>> >
> >> >>> > Hello,
> >> >>> >
> >> >>> > On 2026-01-14 14:59, Simon Matter via sane-devel wrote:
> >> >>> >> These scanners work perfectly fine with very old sane-backends
> >> >>> >> and operating system.
> >> >>> >
> >> >>> > Does it work on the exact same computer
> >> >>> > where it fails or does it work on old computers?
> >> >>>
> >> >>> It works fine on old computers with old software.
> >> >>>
> >> >>> >
> >> >>> > I ask because of possible USB 3 related issues, see
> >> >>> > https://en.opensuse.org/SDB:Configuring_Scanners#USB
> >> >>>
> >> >>> Thanks, I'll check it out.
> >> >>>
> >> >>> Simon
> >> >>>
> >> >>>
> >> >>>
> >> >>
> >> >> --
> >> >> "well, I stand up next to a mountain- and I chop it down with the
> >> edge
> >> >> of
> >> >> my hand"
> >> >>
> >> >
> >>
> >>
> >>
> >
> > --
> > "well, I stand up next to a mountain- and I chop it down with the edge of
> > my hand"
> >
>
>
>

-- 
"well, I stand up next to a mountain- and I chop it down with the edge of
my hand"
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