Date: Sun, 29 Oct 1995 20:48:46 +0100 From: se@zpr.uni-koeln.de (Stefan Esser) To: davidg@Root.COM Cc: CVS-commiters@freefall.freebsd.org, cvs-sys@freefall.freebsd.org, matt@lkg.dec.com Subject: Re: cvs commit: src/sys/pci if_de.c Message-ID: <199510291948.AA25515@Sysiphos> In-Reply-To: David Greenman <davidg@root.com> "Re: cvs commit: src/sys/pci if_de.c" (Oct 28, 4:25)
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On Oct 28, 4:25, David Greenman wrote: } Subject: Re: cvs commit: src/sys/pci if_de.c } >There is a global variable for the purpose of determining } >the maximum burst length. It is currently initialized to } >4 longwords, but I guess having it default to 8 would be } >Ok. (We reduced it to 4 because of a problem reported by } >Matt Thomas with an old Saturn chip set revision). } } So what is the conclusion - is it safe to increase the default burst size } to 8 longwords, or does this indeed cause problems for the Saturn chipset? I've never seen a problem with 8 longwords, the limitation to 4 was put in on Matt's advise, since he made them responsible for problems he had observed ... The NCR uses the burst length as a mask. If so many low order bits are zero, it will start another burst. I.e. it won't cross cache boundaries. Wolfgang's old ASUS SP3 (with the old rev. of the Saturn) worked fine with 8 longwords, too, BTW. Regards, STefan -- Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021 Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160 ============================================================================== http://www.zpr.uni-koeln.de/~se <se@ZPR.Uni-Koeln.DE>
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