Subject: Re: [PATCH] powerpc/mpic: Remove WHOAMI readback after EOI

From: Scott Wood <[email-masked]>
Date: Wed, 13 May 2015 11:33:57 -0500

On Wed, 2015-05-13 at 15:23 +0300, Purcareata Bogdan wrote:
> Ping?
> 
> On 24.03.2015 12:43, Bogdan Purcareata wrote:
> > After previous discussions regarding the subject [1][2], there's no clear
> > explanation or reason why the call was needed in the first place. The sensible
> > argument is some sort of synchronization between the CPU and the MPIC, which
> > hasn't been pointed out precisely and is no longer required (at least on BookE
> > platforms).
> >
> > The benefit of this change is saving a MMIO trap per interrupt when running in a
> > KVM guest.
> >
> > [1] https://patchwork.ozlabs.org/patch/429098/
> > [2] https://patchwork.ozlabs.org/patch/433557/
> >
> > Signed-off-by: Bogdan Purcareata <[email-masked]>
> > ---
> >   arch/powerpc/sysdev/mpic.c | 1 -
> >   1 file changed, 1 deletion(-)

Don't top-post.

This is commit 56302c53d3dc477b8360954fc92c1dfc4fc0ec54 in Linus's tree.

-Scott