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 <[email protected]> > 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 <[email protected]> >> > 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 < >> >> >> [email protected]> 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" >
