[sane-devel] Unable to access minor data

Henning Meier-Geinitz henning@meier-geinitz.de
Tue, 3 Dec 2002 22:53:05 +0100


On Tue, Dec 03, 2002 at 09:30:00PM +0000, Alexis wrote:
> On Tuesday 03 December 2002 9:08 pm, Henning Meier-Geinitz wrote:
> >
> > Did you do "rmmod scanner" before? Otherwise the modprobe does nothing.
> >
> I did.  I just rebooted and tried it again too!  That puts me in mind, is 
> there anything I could maybe pass via lilo to the kernel?

I don't think so.

> > You should see error messages in syslog if it can't handle this device.
> >
> Only that it is not claimed by any active driver.

That's not a meassge from the scanner driver but from usb.c.

You should see at least the following messages:
kernel: usb.c: registered new driver usbscanner
kernel: scanner.c: probe_scanner: User specified USB scanner -- Vendor:Product - 55f:21d
(if you are lucky: kernel: usb.c: usbscanner driver claimed interface d74c2624)
kernel: scanner.c: 0.4.9:USB Scanner Driver

> I would have thought that the kernel patch would be designed to cope
> with this anyway. 

The kernel patch adds some functions to communicate with the scanner
but they don't change the detection code.

> The driver also requires some support files taken from windows, which
> I assume also factor into supporting this. 

But these files are only necessary for the backend, not the kernel
scanner driver.

> The thing about endpoints is completely meaningless to me, I'm
> afraid! Somehow I think I am going to learn anyway.... :-)

Think about how data is transfered to and from the scanner. This
scanner has two pipes (ways, streets whatever) to get data from the
scanner and one to move data to the scanner. The most common case is

> Is it possible that the scanner is faulty? 

Maybe, but that would be very unlikely, because it is detected by the
kernel. It's just not detected by the scanner module.

> In such a way that it will work with windows but not with Linux?

Most likely not. But maybe the scanner driver has to be modified to
accept this scanner.

If the endpoint issue is the cause for not detecting it you'll get the
following message in syslog:

probe_scanner: Undetected endpoint -- consult Documentation/usb/scanner.txt