[sane-devel] scanimage timeouts

Marcel Pol mpol@gmx.net
Tue, 21 Jan 2003 18:29:25 +0100

On Tue, 21 Jan 2003 13:14:12 +0100
Henning Meier-Geinitz <henning@meier-geinitz.de> wrote:

> On Tue, Jan 21, 2003 at 11:06:35AM +0100, Marcel Pol wrote:
> > I currently use Sane 1.0.9, and when I enable all backends it takes a long
> > time to run scanimage -L
> That's a known issue of the Linux USB scanner driver. The problem is
> that the scanner driver issues an error for each device file that it
> doesn't know about. Check your syslog. If you have /dev/usb/scanner0 -
> /dev/usb/scanner15 but only one scanner, there will be syslog entries
> for devices 1-15. And this is repeated over and over again for each
> test. Check your syslog.
> Fix (downgrade this error to a dbg) is in Linux 2.4.21-pre3. Or get
> the latest code from http://www.meier-geinitz.de/kernel/.

I'm currently using 2.4.21-pre3, that's what I used this morning also.
I don't have any devices listed under /dev/usb, because Ii use devfs, which
only ceates dev files when devices are there.

> Possible work-arounds:
> - Use libusb instead of scanner module (you may need sane 1.0.10-pre2
>   for this to work with all backends).

I could try this, and see how it works. All usb scanners should be supported
by it?

> - disable "usb vendor product" lines in backend .conf files and use
>   hardwired device names instead (e.g. /dev/usb/scanner0)

I noticed the snapscan driver has a lot of these lines. Can these be
uncommented, since they are integrated into the scanner kernel driver? Even if
I had such a scanner?
I'm not just asking for myself. In the Mandrake packages all drivers are
disabled by default, and can be enabled by scannerdrake, a config utility.
This is not the way it should be....

> > I ran Xsane with sane_debug_dll=128, and I experienced long timeouts with
> > these backends:
> > 
> > snapscan:  9 seconds
> > plustek:	 15 seconds
> These are backends that test for lots of USB scanners.
> > dc210:  11 seconds
> > dc25:  30 seconds
> That's a different problem (not an USB device). Also, these backends
> are disabled by default.

Ok, if they are disabled by default, I just forget about them.

Marcel Pol