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Date: Tue, 13 Dec 2016 13:15:14 -0600
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Paul Mackerras <paulus@samba.org>,
 Michael Ellerman <mpe@ellerman.id.au>, Scott Wood <oss@buserror.net>,
 Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>,
 Arnaldo Carvalho de Melo <acme@kernel.org>,
 Alexander Shishkin <alexander.shishkin@linux.intel.com>,
 linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC 1/2] powerpc/32: Unset MSR RI in exception epilogs
Message-ID: <20161213191514.GJ30845@gate.crashing.org>
References: <cover.1481652710.git.christophe.leroy@c-s.fr>
 <e6292c23163fac0865def3a385ff01d1497b005b.1481652710.git.christophe.leroy@c-s.fr>
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On Tue, Dec 13, 2016 at 07:19:41PM +0100, Christophe Leroy wrote:
> At exception prologs, once SRR0 and SRR1 have been saved, MSR RI is
> set to mark the interrupt as recoverable.
> 
> MSR RI has to be unset before writing into SRR0 and SRR1 at exception
> epilogs.

Why?  What goes wrong without this?  Etc.


Segher