Subject: Re: DECchip 21143 and the tlp driver.
To: Brad Spencer <>
From: Wolfgang Rupprecht <>
List: current-users
Date: 10/29/1999 14:38:50
> I tried the above, but it didn't seem to matter.  No amount of ifconfiging
> can cause the media type to change.

I just went to the console of my DFE-570TX machine and tried the
ifconfig.  I can confirm that the adaptor itself stays in the
100baseTX mode while the kernel thinks it is now 10baseT.

Ping to a 10baseT host:
      16008 bytes from icmp_seq=0 ttl=0 time=29.370 ms

Ping to a 100baseTX host:
      16008 bytes from icmp_seq=0 ttl=0 time=3.858 ms

Since the pings to the 100baseTX host are ~10x faster, it looks like
the interface is still speaking 100BaseTX.  Interesting.

> The fifo changes start to occure around the time that the quotas are being
> checked.  The machine in question has 3 scsi busses on it, and a couple of
> them would be active checking the quotas.  It appears that any amount of
> traffic at this time causes the fifos to adjust.

I can believe that 3 scsi buses would chew up all of one's PCI bandwidth.

I wonder if there is any pci bus coupler tweaking that can be done by
software to allow devices to get on and off the bus a bit faster.

Wolfgang Rupprecht    <>
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