[sane-devel] Problem with Canon Lide 220 scanner / sane / genesys: Device busy after computer start

[thillosen at free.fr]

I'm experiencing problems with a Canon Lide 220 scanner.
Everything worked fine right without any tweaking when I was in an older 
version of Linux Mint Mate Edition (based on Ubuntu).
Since I updated to Linux Mint Mate 20.2 ("focal"), I'm now experiencing 
weird behavior with my scanner.
My Canon Lide 220 scanner is handled by sane and genesys.

After booting, lsbusb can see my scanner:
Bus 001 Device 003: ID 04a9:190f Canon, Inc. CanoScan LiDE 220

sane-find-scanner is also able to find it correctly:
found USB scanner (vendor=0x04a9 [Canon], product=0x190f [CanoScan], 
chip=GL848+) at libusb:001:003

But scanimage -L is failing to list any scanner.
It doesn't report any error, even if I call it with SANE_DEBUG_DLL=5

Interestingly, if I try:
scanimage --device "genesys:libusb:001:003" --format=tiff > test.tiff
Then it reports me: "Failed: device busy".

I found a weird bypass to get the scanner working:
If I keep pushing the physical "Send" button on the scanner and then 
start a scan program on the computer, eventually, it may start working.
Then, once one scan worked, I don't need to play with the physical 
buttons on the scanner anymore: I can do any scans I want directly from 
the computer.

I never had this problem before.
Previously, I was able to start scans from the computer, without having 
to feedle with the physical buttons on the scanner.

Currently, I'm using libsane-1.0.32-focal0, libsanecommon-1.0.32-focal0 
and sane 1.0.14-15

Is this a bug in my version of sane?
Or do I need to configure something to fix this problem?
Please ask if you want me to log additional details.

Thanks,

Andreas THILLOSEN