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Date: Wed, 7 Mar 2007 14:40:26 +0530
From: Mohan Kumar M <mohan@in.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH] Fix interrupt distribution in ppc970
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Cc: ppcdev <linuxppc-dev@ozlabs.org>, Nathan Lynch <ntl@pobox.com>,
	Paul Mackerras <paulus@samba.org>, fastboot@lists.osdl.org
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On Wed, Mar 07, 2007 at 09:52:47AM +0100, Benjamin Herrenschmidt wrote:
> On Tue, 2007-03-06 at 16:05 -0600, Nathan Lynch wrote:
> > Was the root cause of this problem ever determined?  It sure looked
> > like a firmware or hardware problem since it's known to occur only on
> > JS20.
> 
> js20 and js21 have in common that the firmware "emulates" the XICS on
> top of an MPIC, which can cause interesting issues ... like the
> requirement of issuing EOI's from the CPU that got the interrupt, among
> ohters.
>

There is no interrupt missing problems in JS21. Only JS20 boxes face this
problem. The only difference between JS20 and JS21 is that JS20 does not
have Global Interrupt Queue while JS21 has GIQ.

Regards,
Mohan.