[sane-devel] Sane doesn't create a scanner device

[russbucket]

On Wednesday 26 October 2005 05:11, Olaf Meeuwissen wrote:
> CC:ing sane-devel for the benefit of archival purposes.
>
> dark_mail at gmx.net writes:
> > Actually, I already have switched to udev. So gathering from your
> > answer I guess iscan and udev don't work together.
>
> Let me put it this way, iscan does not have any udev support so when
> you plug in your device udev may not recognise it as a scanner.  The
> upshot of that is that the device node may not get the permissions
> needed iscan and other SANE frontends to access it.  You will need
> read and write access to the device for it to work.
>
> Just to make sure, check that the /proc/bus/usb/###/### entry that
> corresponds to your RX420 has read/write access for everyone.  If it
> doesn't, then, as root, do
>
>   # chmod 0666 /proc/bus/usb/###/###
>
> and give it another try.
>
> # For the security conscious boys and girls out there, I know that
> # this is not a good idea in general, but we're just trying to get
> # the damn thing to work here first.
>
> > I tried again to make the scanner work, without result. It makes no
> > difference if I'm a normal user or root, neither the with epson- nor
> > with the iscan-backend I get it to work.
>
> Now, if it also doesn't work when you are root, then there may be
> something else that is getting in your way because root normally can
> do anything to the device.  i say normally, because SELinux and the
> like may throw a spanner in the works here.  For now I'm assuming you
> are using the good old Unix ACL mechanism.
>
> > The node at /proc/bus/usb/001/ is there, but I can't use it in any way.
> > Creating a link from the respective node to something in /dev/ didn't
> > help me, either.
>
> With /proc being a virtual file system, I'm surprised you managed to
> make it a symlink to anywhere else to begin with.
>
> > But I can't believe I'm the only one not able to make it work!
>
> Actually, there is another thread going on (started by russbucket,
> IIRC) that just may be related to this (at least as far as iscan is
> concerned).
>
> > What do you think: Is udev the reason? Is it something else? Is it me?
>
> Nah, it's probably the weather or the phase of the moon ;-)
>
> Seriously, sane-backends should have reasonably working udev support,
> but I vaguely recall seeing some udev related commits recently.  You
> may want to check CVS for the latest scoop on this.
>
> > I have updated my sane-backend to version 1.0.16, didn't help.
>
> That version introduced a locking mechanism which may or may not be
> enabled by default on Gentoo.  I don't know the details (yet).  Any
> one else care to jump in?  Henning?
>
> BTW, the epson backend in that version should support your scanner out
> of the box.  In 1.0.15 it did not, but you could force support for it
> by adding
>
>   usb 0x04b8 0x080f
>
> to your /etc/sane.d/epson.conf.
>
> > I even installed iscan from rpm (which normally isn't a good idea when
> > you use portage for all other packages).
> >
> > I'm close to despair!
>
> I can tell from your installation from RPM ;-)
>
> > Olaf Meeuwissen wrote:
> >> Karl Heinz Kremer <khk at khk.net> writes:
> >>>You need to configure your hotplug system - this will then create the
> >>>scanner device for you once the scanner is connected to the system.
> >>>I'm not familiar with Gentoo, so I don't know how this is done with
> >>>your system.
> >>
> >> There most likely will be a dynamically created device by the name of
> >>
> >>   /proc/bus/usb/001/004
> >>
> >> but it may not have the correct permissions.  You need read and write
> >> permissions for the user that wants to use the scanner.
> >>
> >> Note that when you re-plug or power cycle the device it will change
> >> "names" (probably to /proc/bus/usb/001/005, 006 and so on).  Unless
> >> you set up hotplug (or udev, which I still have to look into myself)
> >> to do this for you, you will need to do this manually every time you
> >> re-plug, power cycle the device or reboot.
> >>
> >> For USB scanners with a recent enough libusb (>= 0.1.6) and kernel (>=
> >> 2.4.12-ish. IIRC) there is no real need to muck with /dev/usb/scanner*
> >> anymore.  For 2.6.x kernels /dev/usb/scanner* is not an option, really.
> >>
> >>>On Oct 24, 2005, at 6:40 PM, dark_mail at gmx.net wrote:
> >>>>I'm using an Epson Stylus Photo RX 420 (scanner-printer-combo) on a
> >>>>Gentoo machine (Kernel 2.6.13).
> >>>>
> >>>>Sane is version 1.0.15 (back- and frontend).
> >>>>
> >>>>My problem is the following:
> >>>>
> >>>>sane-find-scanner detects my scanner correctly:
> >>>>
> >>>>found USB scanner (vendor=0x04b8 [EPSON], product=0x080f [USB MFP]) at
> >>>>libusb:001:004
> >>>>
> >>>>But I don't find a device for the scanner anywhere. I even created a
> >>>>/dev/usb/scanner0 by hand, but that didn't help me, either.
> >>>>
> >>>>I also tried iscan, but it only says that it can't connect to the
> >>>>scanner and that I should make sure the scanner is on.
> >>
> >> What version?  If you take care of the hotplug support it provides,
> >> most of the EPSON scanners should work out-of-the-box (unless your
> >> system has already switched to udev in favour of hotplug).
> >>
> >>>>[snip]
> >>
> >> Hope this helps,
>
> --
> Olaf Meeuwissen
> FSF Associate Member #1962           sign up at http://member.fsf.org/
> GnuPG key: 30EF893A/2774 815B DE83 06C8 D733  6B5B 033C C857 30EF 893A
> Penguin's lib!       -- I hack, therefore I am --               LPIC-2
I found an item on Novell that says SuSE 10.0 only uses udev not hotplug. When 
I look at udev there are entries for a usbscanner in 50-udev.rules. I noticed 
the permissions are 644 so I'm going to try changing them to 0666. 

If I add my CX6600 (oxo4b8 0x0813 to the epson.conf and uninstall iscan do you 
think it will work? is it better to run iscan-free? I don't care anymore if I 
use Iscan and epkowa or what as long as I get something working. I tryed the 
suggestion of disabling my usblp, but it did not help.

How do you switch to udev and disable hotplug when novell say hotplugs not 
used?

I see no scanner created for my CX6600 but the printer and usb disks are.

Thanks for everyones continuing help.