[sane-devel] Acer Vuego 310s (scsi) under FreeBSD

abel deuring a.deuring@satzbau-gmbh.de
Sun, 23 Sep 2001 15:50:38 +0200

Henning Meier-Geinitz wrote:
> Hi,
> On Sat, Sep 22, 2001 at 07:57:32AM +0200, Hans Eichbaum wrote:
> > I've some troubles with my Acer Vuego 310s scanner.
> > The scanner have worked properly under Suse Linux & sane.
> > but under FreeBSD I've got a strange message when starting scanimage or xsane
> > namely
> >
> > Failed to start scanner : Error during device I/O
> >
> > in my /var/log/messages I find the following :
> >
> > Sep 22 01:32:29 cp8772-b /kernel: cam_periph_mapmem: attempt to map 122400
> > bytes, which is greater than DFLTPHYS(65536)
> I'm not sure if this is related, but you may try to set the
> environment variable SANE_SG_BUFFERSIZE to a smaller value (e.g. 65000
> in this case). See man sane-scsi for details.

Hi Henning and Hans,

Right, the error sounds like the snapscan backend tries to read more
data with one command than supported by FreeBSD. But setting
SANE_SG_BUFFERSIZE is only useful for Linux; for other operating systems
Sane has no support for changing the maximum buffer size for SCSI data
-- the backends must use 

"grep sanei_scsi_max_request_size snapscan*.[hc]" does not return any
results, so I guess the bug is within the Snapscan backend. Perhaps it
simply tries to read entire scan lines with one SCSI command; in this
the limit of 65536 bytes can easily be reached for higher scan