From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v4 10/10] ARM: sunxi: smp: Add initialization of CNTVOFF Date: Mon, 19 Mar 2018 14:55:05 +0100 Message-ID: <20180319135505.py4evmbexm2asvlo@flea> References: <20180223133742.26044-1-mylene.josserand@bootlin.com> <20180223133742.26044-11-mylene.josserand@bootlin.com> <6329fbb6-13a1-41fe-f6cf-f2f0d4b2e5f9@arm.com> <20180318200715.363f3135@dell-desktop.home> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Chen-Yu Tsai Cc: =?utf-8?Q?Myl=C3=A8ne?= Josserand , Marc Zyngier , Russell King , Rob Herring , Mark Rutland , devicetree , quentin.schulz@bootlin.com, linux-kernel , LABBE Corentin , Thomas Petazzoni , linux-arm-kernel List-Id: devicetree@vger.kernel.org On Mon, Mar 19, 2018 at 10:14:19AM +0800, Chen-Yu Tsai wrote: > On Mon, Mar 19, 2018 at 3:07 AM, Mylène Josserand > wrote: > > Hello Mark, > > > > Please, excuse me for this late answer and thank you for the review! > > > > On Wed, 7 Mar 2018 12:18:33 +0000 > > Marc Zyngier wrote: > > > >> On 23/02/18 13:37, Mylène Josserand wrote: > >> > On Cortex-A7, the CNTVOFF register from arch timer is uninitialized. > >> > >> Only on A7? Is that specific to your platform? > > > > I do not really know other Allwinner's platforms about this subject. At > > least, the sun9i-a80 which is a Cortex-a15/a7 does not need that but it > > is necessary for sun8i-a83t which is a cortex-a7. Maybe, Chen-Yu or > > Maxime could help us on it. > > AFAIK all Allwinner CPUs need it if there isn't a firmware (PSCI) layer > beneath the kernel that will do the setup. We just have > "arm,cpu-registers-not-fw-configured" set for all the other SoCs that > have in-kernel SMP support, which includes the A31, A23, A33 and A80. Most of these ones are here for historical reasons though. Now that we have U-Boot properly setting it up, we could probably remove it. Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com