Date: Mon, 22 Feb 1999 02:09:38 -0500 (EST) From: Bill Paul <wpaul@skynet.ctr.columbia.edu> To: dg@root.com Cc: hackers@freebsd.org Subject: Re: How to handle jumbo etherney frames Message-ID: <199902220709.CAA14944@skynet.ctr.columbia.edu> In-Reply-To: <199902220110.RAA15394@implode.root.com> from "David Greenman" at Feb 21, 99 05:10:15 pm
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Of all the gin joints in all the towns in all the world, David Greenman had to walk into mine and say: > >Programming the chip to use a single vlan tag wouldn't require that much > >work. > > Whether to use a VLAN and/or which VLAN to use is a per destination thing, > not a per host/interface thing, so I don't think a single VLAN would be > very useful. Well, supposedly we have some vlan support code in /sys/net/if_vlan.c. What are the odds of getting this to work with for this purpose? > >I'm not really inclined to just implement only standard frame support > >and wait around for large mbuf cluster support to materialize since there's > >no telling how long that could take. I think I may be stuck between a > > Then implement large mbuf support. :-) That's not even remotely funny. All I want to do is write a device driver. That's enough work as it is. You're the principal architect; _you_ implement large mbuf support. > Using malloc for this is probably not a good idea since it wants to > allocate power of two sizes, so you'd needlessly waste a whole page. This > really needs a special allocator specifically designed to deal with the > needs of large mbuf clusters. Again, I think using the external mbuf storage > mechanism is the right way to glue this in. I'm not going to build a whole memory allocator/management subsystem into this driver. Until something else comes along, malloc() will have to do. > One other comment...when I was looking at this stuff I came to the > conclusion that supporting the Tigon 1 was a waste of time since it appears > to be obsolete. Support for just the Tigon 2 should simplify the driver. I disagree. The differences between the Tigon 1 and the Tigon 2 are not that extensive. The Tigon 1 doesn't support the mini receive ring, there are one or two commands that have changed, and you need to load a different firmware image, but for the most part operation is the same. I'd much rather be able to say that the driver supports both chip revs than save a few lines of code. -Bill -- ============================================================================= -Bill Paul (212) 854-6020 | System Manager, Master of Unix-Fu Work: wpaul@ctr.columbia.edu | Center for Telecommunications Research Home: wpaul@skynet.ctr.columbia.edu | Columbia University, New York City ============================================================================= "It is not I who am crazy; it is I who am mad!" - Ren Hoek, "Space Madness" ============================================================================= To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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