From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Thu, 14 Aug 2014 17:02:12 +0100 Subject: [PATCH v7 3/8] drivers: cpuidle: implement DT based idle states infrastructure In-Reply-To: References: <1407945127-27554-1-git-send-email-lorenzo.pieralisi@arm.com> <1407945127-27554-4-git-send-email-lorenzo.pieralisi@arm.com> <20140813170440.GA30822@e102568-lin.cambridge.arm.com> <20140814112911.GA5039@red-moon> Message-ID: <20140814160212.GA5328@red-moon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Aug 14, 2014 at 04:47:57PM +0100, Nicolas Pitre wrote: > On Thu, 14 Aug 2014, Lorenzo Pieralisi wrote: > > > On Wed, Aug 13, 2014 at 06:29:49PM +0100, Nicolas Pitre wrote: > > > So if you tell me a messed-up DT won't bear much consequences then I'm > > > fine with that. > > > > Nico, on second thoughts, since Ashwin raised the point too and I think > > that at these early stages it might turn out useful, I gave coding > > the check a go. I tried to make the check self contained so that we can > > yank it out if we do not want it in the final version or we will want > > to remove it later. > > > > Here the refreshed patch is: > > > > -- >8 -- > > Subject: [PATCH] drivers: cpuidle: implement DT based idle states > > infrastructure > > > > On most common ARM systems, the low-power states a CPU can be put into are > > not discoverable in HW and require device tree bindings to describe > > power down suspend operations and idle states parameters. > > > > In order to enable DT based idle states and configure idle drivers, this > > patch implements the bulk infrastructure required to parse the device tree > > idle states bindings and initialize the corresponding CPUidle driver states > > data. > > > > The parsing API accepts a start index that defines the first idle state > > that should be initialized by the parsing code in order to give new and > > legacy driver flexibility over which states should be parsed using the > > new DT mechanism. > > > > The idle states list is obtained from the first cpu in the driver > > cpumask, which implicitly means the parsing code expects idle states > > (and related list of phandles) to be the same for all CPUs in the > > CPUidle driver mask. The kernel does not check this assumption, it must > > be enforced by the bootloader to ensure correct system behaviour. > > Is this last sentence still true? Nope, you are right. Fixed the commit log, a stale comment in the code and dt nodes ref counting, if I get no additional comments I will post this patch with v8, that should be final. Thank you !!! Lorenzo