> -----Original Message----- > From: owner-linuxppc-embedded at lists.linuxppc.org > [mailto:owner-linuxppc-embedded at lists.linuxppc.org]On Behalf > Of Adisorn > Ermongkonchai > Sent: Monday, June 07, 2004 1:21 PM > To: Mark Chambers > Cc: linuxppc-embedded at lists.linuxppc.org > Subject: Re: Poor 8260 FCC Ethernet performance > > > > --- Mark Chambers <markc at mail.com> wrote: > > 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 Chambers > > > It 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/
