Tulip chip on Pentium VME Processor - media autoswitch probs

[Steve Hersey]

     I'm setting up RedHat 5.0 on a VMEbus Pentium processor (VMIC's 
     VMIVME7588-991); it's basically an AT clone on a VME card, with a PCI 
     VME interface chip, and ...
     
     a DEC 21143 Ethernet chip.
     
     I've succeeded in bringing up the system using the Tulip 0.98h driver 
     (which thinks it's talking to a 21140 chip), BUT I keep getting error 
     messages of the following form (even with an idle system):
     
       eth0: 21140 transmit timed out, status f8260400 SIA 000000c4   
       ffffff7f 8ff40008, reseting...
     
       eth0: transmit timed out, switching to 100BaseTX media.  
     
     My network is a 10BaseT system, and it looks like the driver is 
     switching media on me (changes in the states of the link status and 
     packet lLEDs tend to confirm this). I'm guessing that the problem 
     arises from a glut of incoming network traffic confusing the NIC. (It 
     certainly isn't that the NIC is sending gobs of data...)
     
     My question is: Is the driver switching media on me, or is it the 
     chip? In either case, how do I prevent this? I've tried the "force 
     media type" mods suggested in the FAQ, and it doesn't help. Media type 
     autoswitch is NOT important to me; reliability is.
     
     I am reluctant to hack the driver source without advice OR a Tulip 
     data sheet, and I can't find the data sheet on DEC or Intel Web 
     sites...
     
     Can anyone advise me?
     
     P.S. Other Linux machines on this network that have different NICs 
     also report "TX error... resetting" on a regular basis.
     
     Regards, Steve Hersey