Re: irqs and last_ipl[2] already set ...

[Rene B. <re...@we...>]

On 2002.10.07 23:37 Ken Tyler wrote:
> Hello,
> 
> > > http://www.thule.no/haynie/ has lots of info about various buster /
> Zorro
> > > problems including one that was nerver fixed.
> >
> > I can't find informations about Buster/Zorro problems here. Can you
> tell
> > me where exactly it is?
> 
> The site is down at the moment.  Attached are two text files, I'm
> assuming
> I got them from the thule.no site but may have found them somewhere else.


Thanks! Very interesting.

It seems that the SCSI-deadlocks has nothing todo with Buster/Zorro. So 
the only thing I can imagine what the cause of this problem is, is the 
CS-PPC itself.
What are the facts? The 53c770 driver causes on some machines the same 
deadlocks as the 53c710. On slower drives (like ZIP/CDROM) the drivers 
seems to work. On faster drives you get deadlocks. It is also curious that 
the deadlocks seems only appear on SCSI.

Maybe the problem has something todo with DMA and/or SCSI synchronous 
mode. Because slower drives (like ZIP/CDROM) running in asynchronous mode 
and don't use much DMA (because they are slow).
The 53c770 uses DMA, but as far as I look through the 53c710 drivers, they 
don't use DMA. But I'm not sure.


Ciao, Renè