Hello, have in mind that on nowadays systems the generic SCSI device node files /dev/sg* do no longer belong only to real SCSI devices but also to whatever other kind of devices, e.g. on my system with a plugged in "Spaceloop XL 4GB" USB stick ------------------------------------------------------------------------- nelson:~ # lsscsi --generic [1:0:0:0] disk ATA ST3120022A 3.04 /dev/sda /dev/sg0 [2:0:0:0] cd/dvd PIONEER DVD-RW DVR-106D 1.10 /dev/sr0 /dev/sg1 [2:0:1:0] cd/dvd PIONEER DVD-ROM DVD-121R 1.00 /dev/sr1 /dev/sg2 [4:0:0:0] disk Sony UMH-U HS-MS 2.12 /dev/sdb /dev/sg3 [4:0:0:1] disk Sony UMH-U HS-CF 2.12 /dev/sdc /dev/sg4 [4:0:0:2] disk Sony UMH-U HS-SM 2.12 /dev/sdd /dev/sg5 [5:0:0:0] disk Spaceloop XL 4GB 8.07 /dev/sde /dev/sg6 ------------------------------------------------------------------------- so that the number of the generic SCSI device node files /dev/sg* may change depending on which device is plugged in first and/or depending on which device is recognized first by the kernel.
Therefore it does no longer work reliable to have a generic SCSI device node file hardcoded in a /etc/sane.d/<backend_name>.conf file. Instead the backends should do scanner autodetection for USB and SCSI and their /etc/sane.d/<backend_name>.conf files should have appropriate defaults. In particular for the "canon" backend we (i.e. Novell/openSUSE) apply this patch: -------------------------------------------------------------------- --- backend/canon.conf.in.save 2006-07-21 09:43:08.000000000 +0200 +++ backend/canon.conf.in 2006-07-21 09:57:03.000000000 +0200 @@ -1,3 +1,12 @@ -#canon.conf -/dev/scanner +# canon.conf +# +# Activate exactly one of the following choices: +# +# Probe on all /dev/sg* devices: +scsi +# +# Probe for "CANON" on all /dev/sg* devices: +#scsi CANON +# +# Probe only on one fixed device: #/dev/sg0 -------------------------------------------------------------------- For more information regarding the "canon" backend have a look at https://bugzilla.novell.com/show_bug.cgi?id=177492 in particular https://bugzilla.novell.com/show_bug.cgi?id=177492#c11 Also see the "device file for "canon" backend in sane-backends 1.0.17" mail on this list in May 2006. According to "man sane-scsi" it seems the SCSI autodetection is not possible for all operating systems? Otherwise it should be possible to have an upstream default /etc/sane.d/canon.conf like ------------------------------------------------------------------- # canon.conf # # Activate exactly one of the following choices: # # Probe on all /dev/sg* devices: scsi # # Probe for "CANON" on all /dev/sg* devices: #scsi CANON # # Probe only on one fixed device: #/dev/sg0 ------------------------------------------------------------------- Or is there another reason why SCSI autodetection should not be done by default? On Oct 28 07:11 m. allan noah wrote (shortened): > edit /etc/sane.d/canon.conf > > put the scanner device file name there. > > allan > > On Thu, Oct 28, 2010 at 6:37 AM, Denis Prost <denis.prost at wanadoo.fr> > wrote: >> ?Hi everyone, >> >> I've got a problem with my canoscan 300 scsi scanner. >> though it appears in sane-find-scanner output : >> -------------- >> ... >> found SCSI scanner "CANON IX-03035B 1.01" at /dev/sg3 >> ?# Your SCSI scanner was detected. It may or may not be supported by SANE. >> Try >> ?# scanimage -L and read the backend's manpage. >> .... >> ------------ >> whatever GUI I use (xsane, kooka, simple-scan...), these softwares don't >> detect it, the only scanner they detect is my webcam. >> To solve the problem, I have to do by hand "ln -s /dev/scanner /dev/sg3" >> each time I plug my scanner in. >> But that does not seem to be a very clean solution. Is that normal ? Kind Regards Johannes Meixner -- SUSE LINUX Products GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany AG Nuernberg, HRB 16746, GF: Markus Rex
