Re: [PATCH] VIA Rhine stalls: TxAbort handling

Ivan G. (ivangurdiev@linuxfreemail.com)
Wed, 15 May 2002 15:52:35 -0600


> I'll take that down as "The patch didn't break anything" <g>. Thanks.

:) Some nice day this card will work.
I know it. It's too bad I don't have time to mess with it right now.

> What I have seen: switching from eeprom default (AMD/MBA backoff on my
> card) to something else (as VIA does) slows things down, but the TxAborts
> are gone. Did you try different backoff algorithms?

The slowdown I was talking about was actually with the new abort/underrun
handling - I had tried it by myself before your patch. That's the what that
quote was about. I think I handled both Abort and Underrun like that.
I'll try that new patch that you're making to retest.

> Also, you may want to try if the backoff bit in TxConfig makes a difference
> for you (may be different with your chip, after all). It's not a one-liner
> like ConfigD, though, since TxConfig gets overwritten in several places.
> On a side note, I'm not particularly happy about the way we stomp all over
> TxConfig when we set the threshold. IMO we should leave the lower 5 bits
> alone.

No, I haven't messed with those bits, to answer Urban and your question.
I've only tried your patch which forces the backoff algortihm to AMD.
Tests sound like a good idea. I'll try something out when I have time - been
busy lately.

> The only data sheet I've seen for the VT86C100A agrees with the code, not
> the comment, so apparantly I don't have access to those more recent docs.
> This code is only used if you enable MMIO, though, which may not be a good
> idea if you already have problems with the driver.

On Urban's question, I test without MMIO so this is not a related issue. I
was merely curious since I don't feel comfortable trusting something which
A) does not match any of the other Rhine-based cards (2's and 3's)
B) says RESERVED in the docs which I have.

Funny, I was going to send you a link to the newer docs, but I ran into the
older ones which I had never seen before. Yes, they do agree with the current
code. Hmm. Perhaps we should ask VIA why it was changed...

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