[sane-devel] USB problems - [was"no devices available"]

[kilgota at banach.math.auburn.edu]

Hi,

Don't know about the scanner, but I do know a bit about the internals of 
libgphoto2. The problem with the scanner is most probably similar to what 
appears to happen with the camera:

With approximately 99% probability, I would say that your problem with the 
camera is a permissions problem. Quite likely, what has happened is that 
the camera and perhaps the scanner also, is not listed in any of the 
appropriate files in /etc/udev/rules.d in spite of the fact that you have 
upgraded udev. Either that, or along with the upgraded udev the rules are 
not what you expect. For example, the libgphoto2.rules might expect you, 
as a user, to belong to a group called "camera" or some variation on the 
same theme. One of the things that you might do to try to localize the 
problem is to try running these devices as root. If that works, then 
definitely it is a permissions problem and you need to create the right 
entries in the libgphoto2.rules file and the libsane.rules files, which 
are suitable for yourself, or if you do find entries in those files for 
these devices (look for the USB Vendor:Product number combination) and it 
wants your userid to belong to some group and it does not, then either add 
yourself to the group or change the rules file to let you do what you 
want. By all means, too, you can contact Ubuntu and ask them just exactly 
what they have in mind about how they intend for things like this to be 
done in Hardy Heron. I do not know how they are handling such things as 
upgrades because I am not using Ubuntu and instead I usually deal with 
things like this by hand-editing the affected files.

Sorry that there are these problems with permissions, but the alternative 
is that these 
problems are not under control and then we would have a Linux with all 
the 
lack of security that is found in Windows. Clearly, none of us want that. 
But in return for the care about security comes some occasional 
inconvenience, in the form of problems like this.

I hope this helps.

Theodore Kilgore


On Fri, 20 Jun 2008, earther at eartherdesigns.com wrote:

> Good news. I have made some progress after upgrading the Hardy udev
> package but still not out of the woods.
>
> lsusb now prints out correctly:
>
> ~$ lsusb
> Bus 008 Device 001: ID 0000:0000
> Bus 007 Device 001: ID 0000:0000
> Bus 006 Device 002: ID 03f0:0205 Hewlett-Packard ScanJet 3300c
> Bus 006 Device 001: ID 0000:0000
> Bus 005 Device 001: ID 0000:0000
> Bus 004 Device 001: ID 0000:0000
> Bus 003 Device 001: ID 0000:0000
> Bus 002 Device 006: ID 04a9:30fd Canon, Inc. PowerShot A610 (normal
> mode)/PowerShot A610 (PTP mode)
> Bus 002 Device 001: ID 0000:0000
> Bus 001 Device 001: ID 0000:0000
>
> And Sane now finds the scanner:
>
> ~# SANE_DEBUG_NIASH=255 scanimage -L
> [sanei_debug] Setting debug level of niash to 255.
> [niash] sane_init
> [niash] Looking for ScanJet 3300C...
> [niash] _AttachUsb: found libusb:006:003
> [niash] niash: _ReportDevice 'libusb:006:003'
> [niash] Looking for ScanJet 3400C...
> [niash] Looking for ScanJet 4300C...
> [niash] Looking for HP ScanJet 4300c...
> [niash] Looking for Snapscan Touch...
> [niash] Looking for Office Scanner USB 19200...
> [niash] sane_get_devices
> device `niash:libusb:006:003' is a Hewlett-Packard ScanJet 3300C
> flatbed scanner
> [niash] sane_exit
>
> However, when launched, Sane spits out this error:
>
> Failed to open device 'niash:libusb:006:002': Device busy.
>
> Any ideas?
>
> FWIW, the camera is having problems too.  Just in case it might be
> helpful, here's the error:
>
> "An error occurred in the io-library ('Could not claim the USB
> device'): Could not claim interface 0 (Operation not permitted). Make
> sure no other program or kernel module (such as sdc2xx, stv680,
> spca50x) is using the device and you have read/write access to the
> device."
>
> Thanks again for your expertise and patience.
>
>
> Quoting "m. allan noah" <kitno455 at gmail.com>:
>>
>> xsane is not the problem, but sane probably is. run this at the
>> command line as root:
>>
>> SANE_DEBUG_NIASH=255 scanimage -L
>>
>> and post the output to this list.
>>
>> allan
>>
>
>
>
>
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