Why does scanning freeze on Ubuntu with SANE after the driver is detected?

[Gary_A]

I’ve been trying to get my old scanner working on Ubuntu 22.04, but every time I try to scan something the software just freezes. I installed the recommended SANE packages and the driver seems to be detected, but the actual scanning process never completes.

[Andrew.D]

I had a similar hang with an old scanner on 22.04. It would sit there after starting a scan, the progress bar barely moved and the UI looked locked for ages.

[KevinDP]

On my setup the driver showed the device but the scan never finished. I tried a few different USB ports and a couple of frontends, and even swapped to the SANE backend, but the job just sat there.

[ScarlettIR]

Sometimes it's not the scanner but the USB autosuspend or a kernel quirk. I watched the process spike CPU for a moment and then idle, no data moved.

[MilaS]

One question: have you checked dmesg for errors around the time you start a scan?