Date: Mon, 8 May 1995 17:05:10 +0100 (BST) From: Paul Richards <paul@isl.cf.ac.uk> To: julian@ref.tfs.com (Julian Elischer) Cc: bde@zeta.org.au, mtaylor@gateway.cybernet.com, hackers@FreeBSD.org Subject: Re: lance Ethernet and > 16 Mb RAM failure Message-ID: <199505081605.RAA04482@isl.cf.ac.uk> In-Reply-To: <199505072008.NAA10606@ref.tfs.com> from "Julian Elischer" at May 7, 95 01:08:13 pm
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In reply to Julian Elischer who said > > 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 Umm, Julian, shut up :-) The lnc is a bus-master driver and the current bounce buffer code you'll find elsewhere isn't appropriate. The comment at the beginning of the driver has been misunderstood. What I meant was when the driver starts dma'ing directly to mbufs then it'll have to check if the mbuf is below 16Mb and implement bounce buffer if it isn't. Since the dma->mbuf code isn't currently enabled that doesn't really apply. In fact, the driver *DOES* pre-allocate its own buffer space during boot regardless of how much memory there is and it even checks that the allocated mnemory is below 16Mb, though I've never checked that this works since I don't have more than 16Mb. I'd be very puzzled if the driver is somehow getting allocated memory above 16Mb at that point of the boot process anyway. I'll try and sort this out. -- Paul Richards, FreeBSD core team member. Internet: paul@FreeBSD.org, http://www.isl.cf.ac.uk/ Phone: +44 1222 874000 x6646 (work), +44 1222 457651 (home)
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