Date: Fri, 8 Jun 2001 19:01:47 -0700 (PDT) From: wpaul@FreeBSD.ORG (Bill Paul) To: Bsdguru@aol.com Cc: freebsd-hackers@freebsd.org Subject: Re: sysKonnect dual gig adapter Message-ID: <20010609020147.1D9E437B401@hub.freebsd.org> In-Reply-To: <e4.162cb0b4.285262f4@aol.com> from "Bsdguru@aol.com" at "Jun 8, 2001 01:18:44 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
> Looking at the description of the sysKonnect dual adapter, its not clear if > this is a real 2 port nic or that the second port is only a failover port. I > have 2 questions for anyone who has one: > > 1) Can this be used as a 2 port gigabit NIC? Yes. You will have two interfaces, sk0 and sk1, which represent the two ports. Each interface operates independently of the other. > 2) Does this NIC have hardware failover (that is, when power is cut the 2 > ports will be physically tied together. I dont know of any PC plug in that > does this, but its a neat feature. No. SysKonnect advertises the cards for use in failover applications with their Windows (and Linux) drivers. However this is a feature of their driver software only: it has nothing to do with the hardware. When I wrote the if_sk driver, I decided that setting it up as a real dual port NIC was more useful. (If you're really curious, go to www.syskonnect.com and download their Linux driver source. It has all of their failover magic in it.) The SysKonnect cards consist of the SysKonnect GEnesis chip and the XaQti XMAC II chip. (XaQti no longer exists, it was assimilated by Vitesse.) The XMAC is a gigabit MAC with a generic bus interface. The GEnesis provides the PCI interface, DMA support, some packet buffering and arbitration. Basically, the GEnesis is what lets you connect the XMAC to a PCI bus. But the GEnesis is designed to support _two_ XMAC chips: it has two sets of DMA queues and two register windows so you can twiddle both XMACs at once. That's how the dual link cards work: there's one GEnesis and two XMACs, and if you have a copper card, two Broadcom copper gigabit PHYs. This is a bit different from the usual multiport NIC design where you have two PCI-based MAC chips and a PCI-PCI bridge. Functionally, this is the same as having a bunch of single-port PCI NICs in their own slots. The SysKonnect multiplexes both MACs through a single PCI slot instead. -Bill To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010609020147.1D9E437B401>