From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni) Date: Mon, 27 Oct 2014 16:12:26 +0100 Subject: [PATCH 12/17] ARM: mvebu: Armada XP GP specific suspend/resume code In-Reply-To: <20141027145939.GD12627@lunn.ch> References: <1414151970-6626-1-git-send-email-thomas.petazzoni@free-electrons.com> <1414151970-6626-13-git-send-email-thomas.petazzoni@free-electrons.com> <20141024142044.GB3142@lunn.ch> <20141024162824.67f9ce3d@free-electrons.com> <20141024145119.GD3142@lunn.ch> <20141027135129.292bd882@free-electrons.com> <20141027141958.GB12627@lunn.ch> <20141027154049.583e4cd2@free-electrons.com> <20141027145939.GD12627@lunn.ch> Message-ID: <20141027161226.199cca96@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Dear Andrew Lunn, On Mon, 27 Oct 2014 15:59:39 +0100, Andrew Lunn wrote: > > Right. But for existing notifier chains, the existence, semantic and > > meaning of the parameters are already defined, and the gazillions users > > of that notifier chain in the kernel rely on those parameters to not > > change. > > That is not really true. Lets start off with: > > https://lkml.org/lkml/2014/10/21/56 > > This is brand new code, implementing the poweroff handler call chain. > Take a look at do_kernel_power_off(). It passes a NULL pointer as the > parameter to the handler function. So there are not gazillions users > of that notifier chain in the kernel rely on those parameters to not > change. Ok now I understand why I didn't see it. This code is not in mainline. And actually, it doesn't seem to be close from hitting mainline when reading the reaction of Rafael Wysocki on the main patch: """ Well, I must admit to having second thoughts regarding this particular mechanism. Namely, notifiers don't seem to be the best way of expressing what's needed from the design standpoint. """ So I'm a bit reluctant to create a dependency of the Armada XP suspend/resume code to a very large unmerged patch series that doesn't seem to even be close of having a consensus amongst the maintainers. Isn't this something we can rework afterwards once the poweroff discussion has settled? I wouldn't mind declaring the particular aspects of the DT bindings related to the PIC GPIOs as "staging", so that we keep the freedom to change them for a few kernel releases until we settle on the final solution for that. Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Subject: Re: [PATCH 12/17] ARM: mvebu: Armada XP GP specific suspend/resume code Date: Mon, 27 Oct 2014 16:12:26 +0100 Message-ID: <20141027161226.199cca96@free-electrons.com> References: <1414151970-6626-1-git-send-email-thomas.petazzoni@free-electrons.com> <1414151970-6626-13-git-send-email-thomas.petazzoni@free-electrons.com> <20141024142044.GB3142@lunn.ch> <20141024162824.67f9ce3d@free-electrons.com> <20141024145119.GD3142@lunn.ch> <20141027135129.292bd882@free-electrons.com> <20141027141958.GB12627@lunn.ch> <20141027154049.583e4cd2@free-electrons.com> <20141027145939.GD12627@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20141027145939.GD12627-g2DYL2Zd6BY@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andrew Lunn Cc: Jason Cooper , Sebastian Hesselbarth , Gregory Clement , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Tawfik Bayouk , Nadav Haklai , Lior Amsalem , Ezequiel Garcia , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Dear Andrew Lunn, On Mon, 27 Oct 2014 15:59:39 +0100, Andrew Lunn wrote: > > Right. But for existing notifier chains, the existence, semantic and > > meaning of the parameters are already defined, and the gazillions users > > of that notifier chain in the kernel rely on those parameters to not > > change. > > That is not really true. Lets start off with: > > https://lkml.org/lkml/2014/10/21/56 > > This is brand new code, implementing the poweroff handler call chain. > Take a look at do_kernel_power_off(). It passes a NULL pointer as the > parameter to the handler function. So there are not gazillions users > of that notifier chain in the kernel rely on those parameters to not > change. Ok now I understand why I didn't see it. This code is not in mainline. And actually, it doesn't seem to be close from hitting mainline when reading the reaction of Rafael Wysocki on the main patch: """ Well, I must admit to having second thoughts regarding this particular mechanism. Namely, notifiers don't seem to be the best way of expressing what's needed from the design standpoint. """ So I'm a bit reluctant to create a dependency of the Armada XP suspend/resume code to a very large unmerged patch series that doesn't seem to even be close of having a consensus amongst the maintainers. Isn't this something we can rework afterwards once the poweroff discussion has settled? I wouldn't mind declaring the particular aspects of the DT bindings related to the PIC GPIOs as "staging", so that we keep the freedom to change them for a few kernel releases until we settle on the final solution for that. Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- 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