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

[m. allan noah]

well, are you normally killing button daemon, or did the problem start
before that?

On Wed, Jan 14, 2026 at 3:54 PM Simon Matter <simon.matter at invoca.ch> wrote:

> There is nothing in dmesg, unfortunately.
> I see that the button daemon does a sane_open() but when it is terminated
> with SIGTERM, there is no sane_close() called from what I understand.
> Could that be problem?
>
> Thanks,
> Simon
>
> > 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"
> >
>
>
>

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