RE: Poor 8260 FCC Ethernet performance
From: VanBaren, Gerald (AGRE) <hidden>
Date: 2004-06-07 17:33:04
quoted hunk
-----Original Message----- From: owner-linuxppc-embedded@lists.linuxppc.org [mailto:owner-linuxppc-embedded@lists.linuxppc.org]On Behalf Of Adisorn Ermongkonchai Sent: Monday, June 07, 2004 1:21 PM To: Mark Chambers Cc: linuxppc-embedded@lists.linuxppc.org Subject: Re: Poor 8260 FCC Ethernet performance--- Mark Chambers <markc@mail.com> wrote:quoted
Hi Adisorn, You should probably try monitoring your network with Ethereal or something similar to see what the problem really is - in other words make sure that the problem really is packets coming out of your board too slowly. Mark ChambersIt is the packet coming out from the board that is slow. But we also found that receiving side is even slower. What was the 8260 FCC performance that you got? According to Dean's response, he could forward at 29000 pps and that was much, much better than ours. Adisorn.
Hi Adisorn: Did you check your settings in the FCC Ethernet Mode Register (FPSMR) bits 3 Local Protect Bit (LPB) and 5 Full Duplex Ethernet (FDE)? In particular, LPB and FDE _MUST_ be set to '1' in full duplex. This has been a problem in the past with FCC ethernet drivers, including the linux driver. 1) If you have a miss-match on full/half duplex between your switch/hub and/or your PHY and/or your FCC, you will have very poor ethernet performance, very similar to what you are complaining about. Your Rx may be delayed/suppressed by Tx packets, or you may see lots of late collisions. 2) Another hint I haven't experienced personally (yet :-) is that, if the board has layout problems between the PHY and the 8260, you can get a lot of CRC errors due to noise messing up your transmissions. I'm guessing that your problem is #1, however. Question: What is your system setup? Hub or switch? PHY configuration is full/half? 10/100? FCC configuration is full/half, LPB = ? FDE = ? Do you see a lot of late collisions in the FCC registers? Do you see a lot of CRC failures? gvb ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/