do not use udev, was: Re: [sane-devel] sane problem with newer kernel

[Roland Kwee]

Hi,

As often, formulating a question is answering it, and here is the 
solution: do not use udev with sane.

I removed the udev config line and now udev does not make the special 
file /dev/usb/scanner on plugging in the usb cable from the scanner. Now 
  sane works as with the older kernel, and I can again use my scanner.

The issue still remains that I would like to see some more info on sane 
with udev, and on how libusb works. Now this is all black magic to me, 
while calling myself an experienced linux user, system manager and 
programmer.

Roland.

Roland Kwee wrote:
> Hi,
> 
> I was using Sane and an Epson Perfection 2400 Photo nicely until I 
> upgraded from linux kernel 2.6.13.3 to 2.6.17.3.
> Now I cannot use the scanner with scanimage or gimp anymore.
> 
> The output of sane-find-scanner changed slightly from:
> 
> 2.6.13.3: found USB scanner (vendor=0x04b8 [EPSON], product=0x011b 
> [EPSON Scanner]) at libusb:001:003
> 
> to:
> 
> 2.6.17.3: found USB scanner (UNKNOWN vendor and product) at device 
> /dev/usb/scanner
> 
> Usbview shows however the correct vendor and product codes.
> 
> Also, udev works better with the new kernel and this line:
> 
> BUS="usb", SYSFS{idVendor}="04b8", SYSFS{idProduct}="011b",
> NAME="usb/scanner"
> 
> that didn't do anything under the older kernel does work under the newer 
> kernel and creates /dev/usb/scanner.
> 
> My impression is that the new kernel does find the scanner at the usb 
> port, but that it introduces a new problem for sane.
> 
> I now have two questions:
> 
> 1) How do I make sane work with /dev/usb/scanner instead of libusb:001:003?
> 
> 2) How do I find out more about libusb? (I fail to find any 
> documentation about libusb, am I looking in the wrong places?)
> 
> Thanks for your help.
> 
> Roland
>