[sane-devel] [sane-devel]device name of libusb

Henning Meier-Geinitz henning@meier-geinitz.de
Sun, 22 May 2005 15:09:20 +0200


On Sun, May 22, 2005 at 09:03:55PM +0800, Roy wrote:
> 1.scanner device name use libusb is like "libusb:nnn:mmm",what is
> scope of nnn and mmm?

nnn defines the USB bus used and mmm the actual device on this bus.
The format is taken from the Linux USB system. You'll find the same
numbers in /proc/bus/usb (nnn is the directory, mmm the file name).
These numbers are NOT the vendor and product ids.

On other operating systems, nnn and mmm can have a different format.

> 2.on a pc,os is redhat8.0,with kenerl 2.4.25. when I use
> sane-find-scanner command,no "libusb:nnn:mmm" in resoult
> information,the information is only " found USB scanner (vendor =
> 0x055f, product = 0x0409) at device /dev/usb/scanner0".so, I cann't
> open device with sanei_usb's sanei_usb_open() function.What can I do?

You are using the kernel scanner driver instead of libusb. Both the
kernel scanner driver and libusb can be used to access scanners.

If sane-find-scanner finds the scanner only as a kernels scanner
driver device (/dev/usb/scanner*) but not as libusb device
(libusb:nnn:mmm), the reason is usually that libusb was not installed
or detected when sane was compiled, or the permissions are wrong
(try as root). Also try to unload the scanner driver ("rmmod scanner").