From owner-freebsd-questions Wed Aug 2 3:46:59 2000 Delivered-To: freebsd-questions@freebsd.org Received: from mail2.netcologne.de (mail2.netcologne.de [194.8.194.103]) by hub.freebsd.org (Postfix) with ESMTP id 7F4FB37B570 for ; Wed, 2 Aug 2000 03:46:55 -0700 (PDT) (envelope-from pherman@frenchfries.net) Received: from bagabeedaboo.security.at12.de (dial-194-8-196-87.netcologne.de [194.8.196.87]) by mail2.netcologne.de (8.9.3/8.9.3) with ESMTP id MAA19411; Wed, 2 Aug 2000 12:46:52 +0200 (MET DST) Received: from localhost (localhost.security.at12.de [127.0.0.1]) by bagabeedaboo.security.at12.de (8.10.2/8.10.2) with ESMTP id e72Akh201669; Wed, 2 Aug 2000 12:46:43 +0200 (CEST) Date: Wed, 2 Aug 2000 12:46:43 +0200 (CEST) From: Paul Herman To: Siegbert Baude Cc: "freebsd-questions@freebsd.org" Subject: Re: Realtek 8139 and DMA? In-Reply-To: <39875E9A.8B9DB8C7@gmx.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 2 Aug 2000, Siegbert Baude wrote: > in LINT I found the hint, that Realtek 8139 is by default in PIO-mode > instead of DMA, because of problems with SMP-machines. > So I commented out: > > /* #define RL_USEIOSPACE */ From /usr/src/sys/pci/if_rl.c: /* * The RealTek 8139 PCI NIC redefines the meaning of 'low end.' This is * probably the worst PCI ethernet controller ever made, with the possible * exception of the FEAST chip made by SMC. The 8139 supports bus-master * DMA, but it has a terrible interface that nullifies any performance * gains that bus-master DMA usually offers. * ...so it may not even be worth it. If you *still* insist on using DMA mode, then I would refer you to Bill Paul, who wrote the driver for the RealTek card. Anyway, after reading the comments in the source, I personally wouldn't trust the DMA mode on a production server. -Paul. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message