Re: DECStation: Support for PMAZ-AA TC SCSI card?

[Ralf Baechle <ralf@oss.sgi.com>]

On Mon, Jul 22, 2002 at 02:21:13PM +0200, Maciej W. Rozycki wrote:

>  I hope so.  I'm begging Ralf for about half a year, sigh...  The subject
> was beaten to death at the list and the feedback looked positive to me
> (after a few doubts were resolved), but Ralf seems to be unhappy with the
> changes due to some ia64 interactions (I'm still not sure which ones,
> though).  Ralf, could you please elaborate? 
> 
>  Otherwise, your case convinces me I should not care about purity or
> cross-platform consistency of code in this area, anymore.  I've been
> observing problems with interrupts due to the lack of iomem access
> synchronization already, but unlike for your PMAZ-A problem, their result
> was more of annoyance than instability.  Since stability is a priority,
> although reluctantly, I will rework the changes to apply to the DECstation
> code only, to keep others happy.  The interface won't change, apart from
> resolving namespace clashes.

We had some discussion with the IA64 guys at SGI on how to handle this
kind of I/O ordering issues.  We never came to a final conclusion but
the proposal was the introduction of separate memory barriers macros for
I/O stuff.  Anyway, I think for the moment we should go with your proposal.

  Ralf