Re: [PATCH] VIA Rhine stalls: TxAbort handling

[Roger Luethi <rl@hellgate.ch>]

On Tue, 14 May 2002 19:47:02 +0200, Urban Widmark wrote:
> The backoff algorithm bits have different names (and possibly different
> meaning) for the vt86c100a.

Not according to my data sheet. You may have been confused by the names I
picked: BackAMD should really be MBA. My upcoming patch will change the
names, i.e. AMD becomes MBA.

> My vt86c100a eeprom sets all backoff bits to 0000, but my vt6102 sets it
> to 0010. Since the eeprom is reloaded when the driver opens, why force it
> to "amd"?

You just answered your question. I did it because on my system that is the
way to trigger aborts and I suspected some cards might come up with a
different default value. VIA is clearing that bit in their driver so I
wouldn't be too surprised if even some newer cards did it, too.

> A module parameter would be nice for testing.

For testing the current solution should do. A parameter would make sense if
we come to the conclusion that it would be beneficial for regular users to
make a selection. It just might be. Maybe somebody who is more opinionated
that me would like to step forward and make that call!?

> Ivan, have you tried playing with these bits?

Have _you_?

> Donalds suggestion is that the TxAborts is simply too much collisions.
> Perhaps the eeprom selection of backoff algorithm isn't working well in
> your environment.

No, it works just great. The problem is that the unmodified driver breaks
down as soon as a TxAbort happens. From my limited experience, MBA seems to
be rather aggressive which is a good thing in some situations (e.g. if
nobody cares that you're monopolizing the network).

Roger