From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH 1/5] ARM: berlin: add SMP support Date: Mon, 2 Jun 2014 12:03:32 +0200 Message-ID: <20140602100332.GH28090@lunn.ch> References: <1401700866-24804-1-git-send-email-antoine.tenart@free-electrons.com> <1401700866-24804-2-git-send-email-antoine.tenart@free-electrons.com> <20140602094715.GG28090@lunn.ch> <20140602100048.GA12162@kwain> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20140602100048.GA12162@kwain> Sender: linux-kernel-owner@vger.kernel.org To: Antoine =?iso-8859-1?Q?T=E9nart?= Cc: Andrew Lunn , sebastian.hesselbarth@gmail.com, thomas.petazzoni@free-electrons.com, zmxu@marvell.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, alexandre.belloni@free-electrons.com, jszhang@marvell.com, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Mon, Jun 02, 2014 at 12:00:48PM +0200, Antoine T=E9nart wrote: > Hi Andrew, >=20 > On Mon, Jun 02, 2014 at 11:47:15AM +0200, Andrew Lunn wrote: > > On Mon, Jun 02, 2014 at 11:21:02AM +0200, Antoine T=E9nart wrote: > > > + > > > +static inline void berlin_reset_cpu(unsigned int cpu) > > > +{ > > > + u32 val; > > > + > > > + val =3D readl(cpu_ctrl + CPU_RESET); > > > + val |=3D BIT(cpu_logical_map(cpu)); > > > + writel(val, cpu_ctrl + CPU_RESET); > > > +} > >=20 > > Is this performing a reset on the CPU, or is it taking it out of re= set? > >=20 > > If you are going to implement CPU hotplug at some point, you are go= ing > > to want to be able to put the CPU into reset, i.e. power it off, an= d > > take it out of reset, i.e. power it on and getting it running. So i= t > > might help if we get these function names clear now. >=20 > It is performing a reset on the CPU. berlin_perform_reset_cpu() then? Yes, that would be better. What happens if the CPU is powered off? Will a reset power it on? Or are you assuming the boot loader has powered it on? Andrew