Date: Wed, 17 Jan 1996 17:01:34 +0100 From: se@zpr.uni-koeln.de (Stefan Esser) To: "Justin T. Gibbs" <gibbs@freefall.freebsd.org> Cc: CVS-committers@freefall.freebsd.org, cvs-sys@freefall.freebsd.org Subject: Re: cvs commit: src/sys/pci ncr.c Message-ID: <199601171601.AA08461@Sysiphos> In-Reply-To: "Justin T. Gibbs" <gibbs@freefall.freebsd.org> "Re: cvs commit: src/sys/pci ncr.c" (Jan 16, 21:30)
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On Jan 16, 21:30, "Justin T. Gibbs" wrote:
} Subject: Re: cvs commit: src/sys/pci ncr.c
} >se 96/01/14 16:10:22
} >
} > Modified: sys/pci ncr.c
} > Log:
} > Make the NCR driver on the boot floppy kernel not negotiate synch. SCSI
} > transfers for CDROM drives.
} >
} > Revision Changes Path
} > 1.57 +3 -3 src/sys/pci/ncr.c
}
} Does config still add a -DKERNEL_NAME to the build process?
AFAIK it still does for 2.1, but
doesn't do it anymore for -current.
I want to suggest some "official"
way to make a kernel abstain from
trying generally useful performance
obtimizations, which might fail in
very rare situations, though.
There should be a kernel variable
(like bootverbose), whose default
value should be set by a kernel
CONFIG OPTION (e.g. using
options FAILSAVEMODE
or something like that) and should
be made available as a BOOT OPTION
(is -f already used ?).
Install kernels must work on as much
(even buggy) hardware as possible,
while the kernel run everyday should
be able to make best use of available
performance features, IMHO.
All INSTALL kernels should default
to failsave, and I'd make this have
the following effects in drivers I'm
working on:
1) switch off NCR tagged commands
(failed for 2 drives in the last
20 months)
2) disable synch. negotiation requests
for CDROM drives (which might be
a show stopper if the drive else
does lock up)
3) PCI might use shorter burst length
or other performance options that
might make an install fail could
be disabled
I don't know which other drivers might
be able to take advantage of such a
feature.
Does this sound reasonable ?
Regards, STefan
--
Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021
Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160
==============================================================================
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