Date: Sun, 7 May 1995 13:08:13 -0700 (PDT) From: Julian Elischer <julian@ref.tfs.com> To: bde@zeta.org.au (Bruce Evans) Cc: mtaylor@gateway.cybernet.com, hackers@FreeBSD.org Subject: Re: lance Ethernet and > 16 Mb RAM failure Message-ID: <199505072008.NAA10606@ref.tfs.com> In-Reply-To: <199505070449.OAA02283@godzilla.zeta.org.au> from "Bruce Evans" at May 7, 95 02:49:52 pm
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so, mtaylor: it looks like you have something you can do for us.. :) get the DMA controlling code from the floppy driver and merge it in with the lnc driver, (or similar) I don't have that board and couldn't test it.... other possible options might be to pre-allocate it's own buffer space during boot if it has > 16MB and use that instead.. or look at the bounce buffer support in the aha driver and copy that? julian > > >> I'm installing 2.0-950412-SNAP on a new system. I've never used the 'lnc' > >> ethernet drivers before, and I'm having difficulty getting them stable on a > >> system with more than 16 Mb of RAM. > >> > >looks as if the bounce buffer code in the dma > >using routines for non master dma, is broken, > >OR maybe they are not using it correctly.... > > >It sould use it's DMA in much the same way as the floppy driver does, > >so that it can guarantee that the DMA will go to a buffer < 16MB > >but this may not be the case.. > > It isn't the case. The TODO list at the start of if_lnc.c says bounce > buffer support will be needed for dma'ing to mbufs above 16MB. > > Bruce >
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