Re: Firewire/sbp2 troubles with Linux 2.6.0

[Ben Collins <bcollins@debian.org>]

> > I'm guessing that your card doesn't like getting some many commands at
> > once. It's possible that your sbp2 device itself cannot handle it
> > (generally, I've found it to be caused by the card though).
> 
> Is it possible to set the limit somewhere between the default and
> complete serialization?  Shouldn't it be possible to detect such
> things automatically, somehow?

Things are attempted to be detected, but somehow that only works 95% of
the time. I'd blame bad sbp2 devices, but I don't have anything to back
that up. You can look in sbp2.c to see where it sets the max commands.

> > As far as 10mbs, you have to remember that even though firewire is much
> > higher than that, your drive is still an IDE, and the firewire is still
> > going through an IDE bridge. So the limitation lies in the IDE bridge.
> > I've seen performance as high as 34MB/s with good IDE bridges and
> > drives, though.
> 
> The disks will easily do 40 MB/s on a good IDE controller.  It seems
> like a rather bad bridge to me if it has that much overhead.  I
> haven't seen many different options for sale, either.

Most things based on newer Oxford chips seem to work pretty well. What
ohci1394 controller do you have though?

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