[sane-devel] How o make genesys backend make use of symlink via udev-rule?

[Kelly Price]

I think the Sane-devel list would know more than what I do.

On Fri, Aug 6, 2021 at 12:50 PM Heinz Rohde <5420108 at mailbox.org> wrote:
>
> Dear Kelly,
>
>
> Hello,
>
> I am very sorry for beeing so short with my detailed information.
>
>
> Here we go:
>
> - The Scanner is a Canon CanoScan LiDE 60
> - The Scanner is
> connected to an ols ThinkPad r60e via USB (All USB ports are USB 2.0)
> -
> The Scanner is handeled by genesys backend.
> - The OS is Debian Buster 64
> bit, all updates installed.
> - The IP number of the Thinkpad is
> 192.168.168.245
>
> - The scanner works locally
> hr at r60e:~$ sudo scanimage -L
> d
> evice `genesys:libusb:002:005' is a Canon LiDE 60 flatbed scanner
>
>
> - The
> scanner works over the network, my 2nd laptop is a Dell E6440 running
> Debian Buster
> hr at e6440:~$ scanimage -L
> device
> `net:192.168.168.245:genesys:libusb:002:005' is a Canon LiDE 60 flatbed
> scanner
>
>
> - This is my udev-rule in /usr/lib/udev/rules.d
>
> less 90-
> scanner.rules
>
> # change device file permission to group scanner for sane
> access
> ATTRS{idVendor}=="04a9", ATTRS{idProduct}=="221c",
> SUBSYSTEMS=="usb", ACTION=="add", MODE="0664", GROUP="scanner",
> SYMLINK+="MyLide60"
>
> but this does not work - it creates no symlink in
> /dev
>
>
>
> - This does work and is my udev-rule in /etc/udev/rules.d
>
> less 83-
> scanner.rules
>
> SUBSYSTEM=="usb", ATTR{product}=="CanoScan",
> ATTR{idProduct}=="221c", ATTR{idVendor}=="04a9", SYMLINK+="myLide60"
> GROUP+="scanner"
>
> It creates a symlink in /dev/
> lrwxrwxrwx  1 root root
> 15 Aug  6 18:18 myLide60 -> bus/usb/002/005
>
>
> It's hardly possilbe to
> document here all the links I visited during the last 5 days, but tere
> are Links that suggested to use
> hr at r60e:~$ sudo scanimage -d
> /dev/myLide60
>
> which obv iously does not work, because a UNIX Device is
> not to be used within the backend systax.
>
> A invocation like
> hr at r60e:~$
> sudo scanimage -d genesys:libusb:/dev/myLide60 results also in an
> error, though it was recommended in a forum blogpost by someone more or
> less savvy.
>
>
> The reason for this is, that I have some windows 10 clients
> in my network.
> They can be used with sane-Scanning-Solution via NAPS2
> Scanning Software and the windows WIA-Sane driver
> https://github.com/mback2k/wiasane/wiki/Downloads
>
> But one need to
> configure the scanning device by hand. Unfortunatly the scanner will be
> assigned deviating USB Bus and Device numbers if the scanner is
> unplugged and replugged or if the scanserver is rebootet. You cannot
> rely on the persistence of USB bus/device number assignment.
>
> That leads
> to the situation, that the users of the windows clients won't be able
> to scan at a certain day or hour noone can predict.
> To assign the then
> valid usb bus / device numbers, you'll have to reinstall the WIA-Sane
> driver each time it is necessary.
>
> Therefore I'd like to have the option
> to configure the windows WIA Sane Driver to the symbolic link.
>
> But until
> today this endeavour was not successful.
>
>
> Important to know:
> SCSI-
> Scanners seem to behave other than USB-Scanners.
> SCSI-Scanners for
> example may have a /dev/sg1, which is a UNIX-Device.
> For SCSI-Scanners
> the symlink may work. I unfortunatly cannot try this out, but several
> postings do claim that.
>
>
> I am now looking for a method to get a
> persistent USB device enumeration for my scanner.
>
> A already tried the
> ALIASES option via dll.aliases.
>
> I wrote this script, which updates the
> dll.aliases in /dev/sane.d
>
> -----
> #!/bin/bash
>
> ALIASFILE=/etc/sane.d/dll.ali
> ases
>
> lsusb | grep LiDE | awk '{ print "alias MyLiDE
> genesys:libusb:"$2":"$4}' | sed 's/.$//' > $ALIASFILE
> -----
>
> The scanner
> then is recognised by its alias, but the windows clients cannot make
> use of it.
> All that the windows WIA Sane Driver sees by autotetection is
> the genesys:libusb:002:005 which I can select as only Option during
> WIA-Sane Setup.
>
>
>
> This is the long version, perhaps you have ideas how I
> should proceed.
>
> THX,
> Heinz
>
> Am Freitag, den 06.08.2021, 08:50 -0400 schrieb Kelly Price:
> > First, run:  sudo sane-find-scanner
> >
> > That'll check if the scanner is identified or not under the current
> > SANE version you have.
> >
> > If that doesn't work, check that your scanner is supported and you're
> > on the latest SANE version (you may need to use the PPA in Ubuntu).
> >
> > If that does work, then the permissions are not set to allow the
> > regular user to use the scanner.
> >
> > Usually you don't need to symlink to the scanner if you're using
> > xsane, so I'd remove your udev rule and see if that helps.  Xsane
> > will
> > scan for your scanner, and if it's the only one, uses it (it'll
> > prompt
> > you otherwise).
> >
> > On Fri, Aug 6, 2021 at 8:37 AM Heinz Rohde via sane-devel
> > <sane-devel at alioth-lists.debian.net> wrote:
> > > Hello,
> > >
> > > I created a symlink via udev rule calles MyScanner and points to
> > > /dev/bus/001/002 (for example)
> > >
> > > I cannot get genesys to use this link, or in other words, scanimage
> > > -d
> > > /dev/MyScanner resukts in an error.
> > >
> > > Any Ideas?
> > >
> > > Thank you,
> > > Heinz
> > >
> > >
> >
> >
>
>


-- 
Kelly "STrRedWolf" Price
http://redwolf.ws