From: broonie@kernel.org (Mark Brown) Date: Thu, 20 Mar 2014 13:43:57 +0000 Subject: [PATCH 1/3] arm64: topology: Add support for topology DT bindings In-Reply-To: <20140320112650.GA1408@red-moon> References: <1395252139-16239-1-git-send-email-broonie@kernel.org> <20140320112650.GA1408@red-moon> Message-ID: <20140320134357.GE11706@sirena.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Mar 20, 2014 at 11:26:50AM +0000, Lorenzo Pieralisi wrote: > On Wed, Mar 19, 2014 at 06:02:17PM +0000, Mark Brown wrote: > > +#ifdef CONFIG_OF > This ifdef can be removed, CONFIG_OF is always selected for arm64 and > the !CONFIG_OF path This has been present since the very first time these patches were posted but hasn't been mentioned as being a problem previously. > > +#else > > +static inline int parse_dt_topology(void) { return 0; } > > +#endif > is wrong, it should return failure. You should remove the CONFIG_OF > ifdeffery. Yup. It actually won't affect the behaviour at present though - since it won't do anything the result will be just the same as if we return an error and reset. Given ACPI (which really looks like it's going to happen at some point and presumably make OF optional) I'm not sure removing the handling of OF is actually constructive but whatever, it's done now... > > + if (leaf) { > > + ret = parse_core(c, cluster_id, core_id++); > > + if (ret != 0) { > > + return ret; > > + } > WARNING: braces {} are not necessary for single statement blocks > #139: FILE: arch/arm64/kernel/topology.c:132: Like I say I don't think checkpatch is being helpful on this one, the code looks worse. Again, whatever. > We still have a problem here. If the topology does not contain bindings > for some cpu nodes, parse_cluster() does not fail and we end up with an > incomplete topology. We have two choices: either we check the topology Hrm, looking at the topology binding it doesn't specificially require that the topology be complete. I can see why you would want that. > I'd rather do it here, in preparation for MPIDR_EL1 fallback solution > (where there will always be topology information configured and the register > will always be there in all its glory). To be honest at this point I think what I want to do is go back to the original approach of layering DT on top of MPIDR. MPIDR is smaller and simpler code so seems more likely to make progress. I really do expect that for a very large proportion of systems it'll be sufficient. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: