Subject: RE: [PATCH] qe_ic: Do a sync when masking interrupts.

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 25 Oct 2006 13:51:14 +1000

On Tue, 2006-10-24 at 15:17 +0800, Li Yang-r58472 wrote:
> > -----Original Message-----
> > From: Scott Wood [mailto:[email-masked]]
> > Sent: Tuesday, October 24, 2006 2:27 AM
> > To: Segher Boessenkool
> > Cc: [email-masked]; Li Yang-r58472; Paul Mackerras;
> [email-masked]
> > Subject: Re: [PATCH] qe_ic: Do a sync when masking interrupts.
> > 
> > Segher Boessenkool wrote:
> > > If a sync after an MMIO write is enough, then (in almost all
> > > cases) so is an eieio.
> > 
> > In this case, the spurious interrupts still happen with eieio, but not
> > with sync.  
> 
> eieio on e300 core is just a no-op.

It's not sent to the bus on non-cahed storage (like the PCI bridge ?)
That's pretty bad ... there is quite a bit of code that assumes that
eieio's will prevent write combining...

Ben.