Date: 29 Jul 1998 17:38:28 -0700 From: Frank McConnell <fmc@reanimators.org> To: Ted Faber <faber@ISI.EDU> Cc: Frank McConnell <fmc@reanimators.org>, Mike Smith <mike@smith.net.au>, Robert Swindells <swindellsr@genrad.co.uk>, hackers@FreeBSD.ORG Subject: Re: AMD PCNet/FAST cards; suppliers? Message-ID: <199807300038.RAA19554@daemonweed.reanimators.org> In-Reply-To: Ted Faber's message of Wed, 29 Jul 1998 10:53:39 -0700 References: <199807291753.KAA12867@tnt.isi.edu>
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Ted Faber <faber@ISI.EDU> wrote: > Frank McConnell wrote: > >Ted Faber <faber@ISI.EDU> wrote: > >>As far as I can tell, there's no support for using the Hitachi's > >>internal PCI lance board in native PCI mode, so the card can only be > >>used in ISA emulation mode. > > > >What led you to that conclusion? Whoops. Poor choice of words on my part -- I wasn't questioning your intelligence when I wrote that, I really wanted to know what behavior you saw on your Hitachi that got you thinking along those lines. > As I mentioned, I'm just msireading the code here. I didn't see > anything that appeared PCI specific, and wasn't seeing my card work. > I'm no expert in either the PCI bus or this chipset - I was just > trying to get the laptop's internal ethernet running so it was of some > use to me. Hey, I'm no expert on these things either, just a wannabe looking for enlightenment. Here's what I was thinking. The probing for PCI and ISA cards looks (and largely is) the same -- I can't see why it should work from one code path and fail from the other, except by way of different I/O base addresses where one doesn't address an appropriate device. So there's one potential problem -- if you have a PCI card, and it's getting mapped at some I/O address for which you have a "device lnc[n]" entry in your kernel config (as for an ISA card), it'll get probed and attached twice. There's also the matter that the IC has a couple of different flavors of modes. One is the "software style" that can be set via BCR20. I think this defaults to C-LANCE/PCnet-ISA on hard reset, and the other styles would expect a different initialization block layout, so I think that this is what the driver expects. The other is word (16-bit) I/O vs. double-word (32-bit) I/O mode, which changes some of the register offsets, and again I think the driver expects to see the IC in word I/O mode (where a hard or soft reset will leave it) and just won't work if the chip is in double-word I/O mode. And there's another potential problem -- if the Hitachi BIOS tells the IC to do some other software style, or puts it in double-word I/O mode, I don't think the driver will probe it correctly. But I think that means both the PCI and ISA probes would fail. (Not that I know why the BIOS would do something like that -- this is speculation on my part.) So that's why I was wondering what you were seeing that would make you think you could use it in "ISA emulation" only -- as near as I can tell it should either work from either code path or not work at all. -Frank McConnell To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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