Re: Anyone with experience scanning with Epson
On Fri 07 Feb 2020 at 11:53:12 -0500, Michael Stone wrote:
> On Fri, Feb 07, 2020 at 03:36:55PM +0000, Brian wrote:
> > On Fri 07 Feb 2020 at 10:25:22 -0500, Michael Stone wrote:
> >
> > > On Fri, Feb 07, 2020 at 03:05:31PM +0000, Brian wrote:
> > > > On Fri 07 Feb 2020 at 09:37:17 -0500, Michael Stone wrote:
> > > >
> > > > > On Fri, Feb 07, 2020 at 10:36:11AM +0800, kaye n wrote:
> > > > > > Hello Friends!
> > > > > >
> > > > > > I'm running:
> > > > > > Kernel: 4.19.0-6-amd64 x86_64
> > > > > > bits: 64
> > > > > > Desktop: Xfce 4.12.4
> > > > > > Distro: Debian GNU/Linux 10 (buster)
> > > > > >
> > > > > > My printer is an Epson L220. It's connected to my laptop's USB port.
> > > > > >
> > > > > > The command lsusb shows:
> > > > > > Bus 002 Device 003: ID 04b8:08d1 Seiko Epson Corp.
> > > > > >
> > > > > > Therefore in the file, /etc/sane.d/epkowa.conf
> > > > > > I added this line:
> > > > > > usb 0x04b8 0x08d1
> > > > > >
> > > > > > The printer can print just fine, but ImageScan and XSane would not run.
> > > > > >
> > > > > > ImageScan says:
> > > > > > Could not send command to scanner. Check the scanner's status.
> > > > > >
> > > > > > XSane says:
> > > > > > Failed to open device 'epkowa:usb:002:003':
> > > > > > Access to resource has been denied.
> > > > > >
> > > > > > Thank you for your time!
> > > > >
> > > > > This smells like a permission problem. In your example above the scanner is
> > > > > on bus 002 device 003. (It may change as you unplug and replug usb devices,
> > > > > so check with lsusb and change the numbers below as needed.) You can see the
> > > > > permissions for that device with:
> > > > > ls -l /dev/bus/usb/002/003
> > > > > If it comes back with something that starts with:
> > > > > crw-rw-r-- 1 root root
> > > > > then it's writable only by root. A working configuration would have either
> > > > > crw-rw-rw- 1 root root
> > > > > or would having your username or a group that you're in rather than root, or
> > > > > would look like
> > > > > crw-rw-r--+ 1 root root
> > > > > indicating an ACL which you can see via getfacl /dev/bus/usb/002/003
> > > > > (there would be a line with your username in the default libsane
> > > > > configuration).
> > > > >
> > > > > Assuming the permissions look like they might be the problem, you can
> > > > > confirm that by running
> > > > > chmod o+w /dev/bus/usb/002/003
> > > > > to make the file world writable (for testing only; it isn't permantent if
> > > > > the scanner is unplugged or the system rebooted). If xsane works, you've
> > > > > found the problem. If that's the case, the next step is probably to update
> > > > > the udev configuration. If not, on to the next guess. :)
> > > >
> > > > Permisions on the USB bus are managed by an ACL.
> > > >
> > > > https://wiki.debian.org/Scanner
> > >
> > > Yes, that's why I mentioned the ACL. :) But, it hasn't always been that way
> > > and it's not the only way that will actually work...hence the other
> > > possibilities.
> >
> > It is the way it is now on unstable/buser/stretch. What is in the past
> > is in the past. No user should have to mess about with permissions or
> > be in the scanner group to have permission to use a USB scanner. If it
> > is a route that is thought to be necessary, there is something wrong
> > with the user's setup or it is a bug.
>
> There's nothing wrong with the user's setup if they have a configuration
> (possibly older) that sets permissions in a way that works even if it isn't
> the current default.
Like protocols, everyone can have their own set of defaults on buster.
In which case, they can sort their own problems out. :)
> I'd rather show someone how they can identify whether
> the permissions are a problem than have them waste their time
> changing things if it isn't even an issue. YMMV.
Indeed. The wiki attempts to do that for a buster user such as the OP.
sane-find-scanner is also a useful tool.
--
Brian.
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