From mboxrd@z Thu Jan  1 00:00:00 1970
From: catalin.marinas@arm.com (Catalin Marinas)
Date: Tue, 17 Dec 2013 11:47:34 +0000
Subject: [PATCH 4/6] arm64: topology: Implement basic CPU topology support
In-Reply-To: <20131216151232.GH3185@sirena.org.uk>
References: <1386767606-6391-1-git-send-email-broonie@kernel.org>
 <1386767606-6391-4-git-send-email-broonie@kernel.org>
 <20131216105734.GA8931@e102568-lin.cambridge.arm.com>
 <20131216122948.GF3185@sirena.org.uk>
 <20131216144638.GE8931@e102568-lin.cambridge.arm.com>
 <20131216151232.GH3185@sirena.org.uk>
Message-ID: <20131217114734.GC32118@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Dec 16, 2013 at 03:12:32PM +0000, Mark Brown wrote:
> On Mon, Dec 16, 2013 at 02:46:38PM +0000, Lorenzo Pieralisi wrote:
> > On Mon, Dec 16, 2013 at 12:29:48PM +0000, Mark Brown wrote:
> [MPIDR parsing]
> > > Again, this is gone from the current version.  Like I said to Catalin it
> > > does feel like this is making more work for systems that have done the
> > > right thing with their MPIDRs which doesn't seem ideal (and note that
> > > all the DTs that you guys are publishing for your models lack any
> > > topology information at present).
> 
> > This is an age-old question and the problem has always been that the
> > "right thing" is recommended, not enforced. I do not want to turn this into
> > bikeshedding, as long as cpu-map node takes priority if present, fine by me.
> 
> I already dropped that code, though I could resurrect it (perhaps as a
> separate patch).  The way the code was written was as you describe as a
> last resort - MPIDR would only be considered if the explict topology
> binding was not present, it was done as a last step before reporting if
> no other topology information was discovered.
> 
> Actually now I think about it if we're not going to parse the MPIDR we
> should probably update the bindings to say that the topology binding is
> mandatory for any v8 system with more than one core.

Do we need such information if only a flat topology is needed?

-- 
Catalin