From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Wed, 17 Apr 2013 10:23:38 -0600 Subject: [RFC PATCH 2/2] ARM: DT: kernel: DT cpu node bindings update In-Reply-To: References: <1366042402-8987-1-git-send-email-lorenzo.pieralisi@arm.com> <1366042402-8987-3-git-send-email-lorenzo.pieralisi@arm.com> <516C544A.4090107@wwwdotorg.org> <20130417091457.GB5012@e106331-lin.cambridge.arm.com> <516EBC66.20508@wwwdotorg.org> Message-ID: <516ECC8A.2070508@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/17/2013 10:02 AM, Nicolas Pitre wrote: > On Wed, 17 Apr 2013, Stephen Warren wrote: > >> On 04/17/2013 03:14 AM, Mark Rutland wrote: >>> Hi Stephen, >>> >>>>> + - enable-method >>>>> + Usage: required on ARM 64-bit systems, optional on ARM 32-bit >>>>> + systems >>>>> + Value type: >>>>> + Definition: On ARM 64-bit systems must be "spin-table" [1]. >>>> >>>> Can that be an integer instead? with dtc+cpp support, that shouldn't >>>> hurt the eyes too much any more. >>> >>> The "enable-method" property is described as a stringlist by ePAPR, and is >>> currently in use on arm64 as such. It *must* remain a string(list) for arm64. >>> >>> Having it as an integer for arm is only going to cause us additional work, >>> makes it impossible to share a common dt between 64bit and 32bit, and goes >>> against the standard. I think it should be a stringlist for arm. >> >> OK, that's a great reason for this case. >> >> I hope we don't introduce any more standards that use strings, but that >> may just be my personal preference... > > I think in any standard, strings are far easier to deal with. > Especially with config stuff which is far from being performance > critical. Strings are much less prone to conflicts. It is too easy to > "extend" a standard by assigning meanings to free numerical values just > to discover that someone else did use the same numbers for other > meanings. > > In order to avoid this issue, a central authority has to be established > to assign numbers out while strings are fine without that most of the > time. For DT, all strings or numbers must always be documented in the DT binding, so there's no risk of conflict there.