From owner-freebsd-hackers Wed Jun 7 17:14:49 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from etinc.com (et-gw.etinc.com [207.252.1.2]) by hub.freebsd.org (Postfix) with ESMTP id DFDC637B8EC; Wed, 7 Jun 2000 17:14:42 -0700 (PDT) (envelope-from dennis@etinc.com) Received: from dbsys (dbsys.etinc.com [207.252.1.18]) by etinc.com (8.9.3/8.9.3) with SMTP id UAA22290; Wed, 7 Jun 2000 20:20:24 -0400 (EDT) Message-Id: <200006080020.UAA22290@etinc.com> X-Sender: dennis@etinc.com X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0 Date: Wed, 07 Jun 2000 20:19:50 -0400 To: Peter Wemm , Mike Smith From: Dennis Subject: Re: if_dc in v4.0 - Forcing store and forward? Cc: hackers@FreeBSD.ORG In-Reply-To: <20000608000153.6AC291CE1@overcee.netplex.com.au> References: <200006072340.QAA01962@mass.cdrom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At 05:01 PM 6/7/00 -0700, Peter Wemm wrote: >Mike Smith wrote: >> > >> > Running a Dlink quad card (570TX) in 100Mb/s full dup mode the driver >> > complains about underruns for awhile and then ultimately sets >> > store_and_forward which seems to make it work. >> > >> > Is there a way to force this easily? It seems that it should certainly be >> > the default if full dup 100 mode is detected as the other settings fail >> > quite easily on rather trivial activities. >> > >> > should this card be used with the if_dc or if_de driver? Both seem to probe >> > it successfully, although both drivers have the same (annoying) underrun >> > problem (that wasnt a problem or at least not screen-verbalized in 3.4). >> >> Transmit underrun is usually caused by another peripheral hogging the PCI >> bus; either a poorly configured card with an excessive latency value, or >> a misconfigured card (due to BIOS bugs), or a card that otherwise ignores >> the PCI latency rules, or a system with too many busy busmaster cards. > >I am yet to see a 2114x based system that does not do this. My sample set >is 21140A (SMC 9332BDT), some 21142's and 21143's. Most Digital labeled >but even the Intel ones do it. This happens in BX chipset, VIA MVP chipsets, >the PC164SX motherboard under SRM, etc. I have even seen frequent underruns >with *no other bus activity* except the CPU fetching code for ttcp and >the busmaster DMA to/from the ttcp processes. ie: no DISK, no VGA cards, >nothing else at all active. I have checked all the latency timers >on all devices as well, they are all set sensibly. > >I suspect a generic chipset fault, or some design quirk that we are not >working around. Note that the windoze drivers for these devices put them >permanently in store-and-forward mode. if_de has the exact same problem on >all of the systems above. Exactly. dennis To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message