Scanner Frustration

[Gerry Tool]

Jim Cornette wrote:
> Gerry Tool wrote:
> 
>> I have been trying to get my Epson 1240U scanner (which works in 
>> everything prior to FC2Tx) to work, following bugzilla report 121511.  
>> It is not clear exactly what needs to be done that seems to work for 
>> some others.  Could someone post a complete step-by-step process to 
>> this list that details how to get usb scanners to work in FC2T3?
>>
>> Having a working scanner is a requirement for me to use FC2 when it is 
>> released.
>>
>> Thanks.
>>
>> Gerry Tool
>>
>>
>>
> 
>  From the "Scanner Access Now Easy" website.
> 
> 
> With Linux 2.4.* you could either use the kernel scanner module or 
> libusb to access USB scanners.  In Linux 2.6.4 the kernel scanner module 
> was removed.
> Therefore with this and later kernels libusb must be used.
> 
> While SANE automatically uses libusb when the library and its header 
> file were present during the build of sane-backends, setting permissions 
> will require *some attention.*
> 
> The device files used by libusb are located in /proc/bus/usb/
> (e.g. /proc/bus/usb/001/003).  The exact file name can be found out by 
> running sane-find-scanner which would print "libusb:001:003" in this 
> case.  While setting permissions with e.g. "chmod a+rw 
> /proc/bus/usb/001/003" seems to work, this change is not permanent.  The 
> permissions will be reset when the scanner is replugged or Linux is 
> rebooted.
> 
> One solution to set permissions on-the-fly are the Linux hot-plug tools 
> that should come with any current distribution.  SANE itsself comes with 
> a hotplug script and related documentaion in the tools/hotplug/ 
> directory. Please refer to the README in that directory for the details.
> 
> 
> My comment:
> Basically, permissions are not setup correctly with libusb. You need to 
> set the permission of whatever device position that sane-find-scanner 
> states. This has to run as root. The file permissions will not recognize 
> the scanner as a normal user.
> 
> Then you have to do what was stated above. I just tried to open my 
> scanner without changing the file permissions and it did not work. I 
> then ran the below command as root.
> 
> chmod a+rw /proc/bus/usb/001/004
> 
> (001 is for the hub. 004 is the port on the hub, for my scanner. This 
> gives the scanner file permissions rw for owner, group and others)
> 
>  ls -la /proc/bus/usb/001/004
> -rw-rw-rw-  1 root root 57 May  3 18:13 /proc/bus/usb/001/004
> 
> 
> I then tried the scanner as a regular user.  It worked after running
> the command.
> 
> There is a new version that I just notified in the bug report mentioned 
> above. Maybe the changes made will make scanner access easy again.
> 
> Hope this is clearer.
> 
> 
Thanks for your reply, Jim.  I changed the permissions, but that did not 
solve the problem.  Another reply from Mike Styne held the other key. I 
needed to change the /etc/sane.d/epson.conf file in a different way from 
all previous releases.  Thanks to the two of you, I now have a working 
scanner.  I did verify that changing the permissions back broke it 
again.  I hope the FC2 release will have this problem solved so that 
users don't have to muck around with either the permissions or the 
details of the xxxx.conf files.

Gerry Tool