[vortex] RX overrun with 3COM 3c982

[Donald Becker]

On Mon, 18 Nov 2002, Claude Pignol wrote:

> >>>>00:08.0 RAID bus controller: 3ware Inc 3ware ATA-RAID (rev 12)
> >>>>
> >>>Hmmm, this might be doing long PCI bursts, not leaving enough for the
> >>>Ethernet.  If that's the case, the solution is to:
> >>>  Change the Min-grant / Max-Latency PCI settings
> >>>  Set the PCI bursts to much longer values, although the '982 has
> >>>    reasonable defaults.  The registers to change are the
> >>>    UpBurstThreshold at offset 0x3e and
> >>>    UpPriorityThreshold, offset 0x3c, default 4*32 = 128 bytes.
...
> >Oh, the external version of vortex-diag only shows up to offset 0x3f,
> >not all of the registers.  You can see some of these values by passing
> >the '-g' option.

OK, I've update vortex-diag as follows to help figure out a way to
improve the PCI performance and minimize this problem:

________________
vortex-diag.c:v2.10 11/19/2002

Show registers up to offset 0x80 instead of 0x40.

Extra casts to avoid warnings from the bogus inl() type change.

Show additional Cyclone state registers when the '-g' flag is passed.
________________

  ftp://ftp.scyld.com/pub/diag/vortex-diag.c
  
> Ratio: .00018 overrun/packet
> But a node without a 3ware controller has also some overrun but the 
> ratio is much smaller
> For the same amout of data transfered:
> R=.000000050 overrun/packet

-- 
Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Scyld Beowulf cluster system
Annapolis MD 21403			410-990-9993