From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Wed, 12 Feb 2014 17:53:08 +0100 Subject: [PATCH v2 0/9] ARM: multi-platform kconfig cleanup and mach-virt removal In-Reply-To: References: <1392153119-23248-1-git-send-email-robherring2@gmail.com> <20140212134655.GC29132@mudshark.cambridge.arm.com> Message-ID: <1726732.KPDAFqxz2K@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday 12 February 2014 08:07:12 Rob Herring wrote: > On Wed, Feb 12, 2014 at 7:46 AM, Will Deacon wrote: > > On Wed, Feb 12, 2014 at 01:26:41PM +0000, Arnd Bergmann wrote: > >> On Tuesday 11 February 2014, Rob Herring wrote: > >> > The previous version [1] was mainly a discussion about v6 vs. v6K. > >> > Several platforms have this wrong and incorrectly select v6 when the > >> > more optimal v6K option could be used. After more research, my memory > >> > about i.MX31 was wrong and it does need to remain v6. > >> > >> Just curious: do you have more information on this? Are all i.MX31 ARMv6 > >> and all i.MX35 v6k as the current Kconfig claims, or is it more > >> complicated? > > > > Slightly tangential, but the one to watch out for is 1136. Prior to r1 (i.e. > > r0pX), it is v6 but r1pX+ are v6k (without SMP). > > Right. I originally was thinking that the MX31 1.x was r0pX and MX31 > 2.x was r1pX and that there are no 1.x chips around. However, after > checking the errata sheet, 1.x is r0p1 and 2.x is r0p4. It must have > been one of the other 1136 chips we did that moved to r1pX. Ok. > >> * integrator and realview apparently allow both CPU_V6 and CPU_V6K > >> to be manually selected. Is that actually the correct behavior > >> in that both kinds of core tiles exist? > > > > I have 1136 r0p1 on an integrator CP, so I suppose it could also take an > > 1136 r1pX without any trouble. > > Presumably some of both exist which is why the config options are as they are? Possible, but I wouldn't trust that part of the kernel very far. Especially the MMU-less CPUs in there seem to be listed a bit randomly. On the topic of V6, we don't support CPU_V6T2 at all, though I assume that there is an ARM1156 core tile for integrator and realview, and we support running the V6/V6K parts with MMU turned off. Would all revisions of ARM1156 work with CPU_V6K and !MMU? Arnd