From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH] drivers: firmware: psci: unify enable-method binding on ARM {64,32}-bit systems Date: Fri, 22 Apr 2016 16:02:23 +0100 Message-ID: <20160422150222.GO10606@leverpostej> References: <1461335911-13233-1-git-send-email-sudeep.holla@arm.com> <20160422144440.GN10606@leverpostej> <571A3BCA.8060002@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <571A3BCA.8060002-5wv7dgnIgG8@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sudeep Holla Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Maxime Ripard , Soby Mathew , Rob Herring , Lorenzo Pieralisi List-Id: devicetree@vger.kernel.org On Fri, Apr 22, 2016 at 03:57:14PM +0100, Sudeep Holla wrote: > On 22/04/16 15:44, Mark Rutland wrote: > >On Fri, Apr 22, 2016 at 03:38:31PM +0100, Sudeep Holla wrote: > >>Currently ARM CPUs DT bindings allows different enable-method value for > >>PSCI based systems. On ARM 64-bit this property is required and must be > >>"psci" while on ARM 32-bit systems this property is optional and must > >>be "arm,psci". > > > >FWIW, "arm,psci" has always been the compatible string for the PSCI > >node, and was never intended to be the enable-method. So as far as I can > >tell, this was a mistake/bug, and not a deliberate attempt at specifying > >32-bit differently. > > I agree. > > >>This is problematic if 32-bit OS is run on 64-bit system which has > >>"psci" as enable-method rather than the expected "arm,psci". > >> > >>So let's unify the value into "psci" and remove support for "arm,psci" > >>before it finds any users. > >> > >>Reported-by: Soby Mathew > >>Cc: Rob Herring > >>Cc: Mark Rutland > >>Cc: Lorenzo Pieralisi > >>Signed-off-by: Sudeep Holla > > > >This was definitely a mistake, as "arm,psci" was the compatible string > >for the psci node, and was never the enable-method. So: > > > >Acked-by: Mark Rutland > > Thanks. > > >Hopefully no-one's begun to use this. > > Seems so. Even the 32-bit kernel doesn't make use of that. > > The first user was for idle(see below) which was added in v4.6 just to > keep it in sync with binding. It would be good to get it fixed before > the final v4.6 Indeed. Lorenzo, how should we forward this on? Do we have any other urgent fixes for v4.6, or should we ask arm-soc to take this alone? Thanks, Mark. > >>diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c > >>index 11bfee8b79a9..b5d05807e6ec 100644 > >>--- a/drivers/firmware/psci.c > >>+++ b/drivers/firmware/psci.c > >>@@ -360,7 +360,7 @@ static struct cpuidle_ops psci_cpuidle_ops __initdata = { > >> .init = psci_dt_cpu_init_idle, > >> }; > >> > >>-CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops); > >>+CPUIDLE_METHOD_OF_DECLARE(psci, "psci", &psci_cpuidle_ops); > > -- > Regards, > Sudeep > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html