> The problem is that a backend may consider sanei_scsi_max_request_size
> as a constant. This was true for the old Linux SG driver; but with the
> new SG driver it is at least in theory possible that you get different
> buffer sizes each time a SG device file is opened. (Not very likely, but
> it is possible)
It's virtually certain if you have two host adapters, whose drivers differ
in their ability to do scatter/gather. This means that SANE will always
fail in that setup.
> Both situations might have caused unnecessary work and headaches for
> backend developers, who don't need or don't want to switch to
> sanei_scsi_open_extended, and therefore I decided to use this "paranoid"
> looking "if (real_buffersize != wanted_buffersize)", when I introduced
> sane_scsi_open_extended and related stuff.
I see, but in the case I mentioned above the user needs to limit the
buffer by setting enviromental variables.
> > Why don't you use sanei_scsi_open_extended if it is available for your
> > paltform? In this case the backend can try to get a big buffer and
> > knows the actual size it is allowed to use.
I am using an existing backend (microtek2). It works with this check removed.
Is converting a backend to use sanei_scsi_open_extended difficult ?
Regards
Oliver
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This archive was generated by hypermail 2b29 : Sun Nov 19 2000 - 09:52:39 PST