Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752647AbdHNODz (ORCPT ); Mon, 14 Aug 2017 10:03:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:35166 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141AbdHNODv (ORCPT ); Mon, 14 Aug 2017 10:03:51 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CC702395B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=robh@kernel.org MIME-Version: 1.0 In-Reply-To: <5d2e3a5e-6060-ff13-a065-c4b6be37e4c9@xilinx.com> References: <8c27b7eec6cc00d37dfe9b3998212ce9c9c27a31.1501854302.git.michal.simek@xilinx.com> <20170810191056.ur5b3zdrcgmb6sim@rob-hp-laptop> <4e5d9f8c-9e87-bdcd-388a-aab3c32415e8@xilinx.com> <20170811135453.GU12347@toto> <5d2e3a5e-6060-ff13-a065-c4b6be37e4c9@xilinx.com> From: Rob Herring Date: Mon, 14 Aug 2017 09:03:29 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/3] dt: xilinx: zynqmp: Add bindings for PM firmware To: Michal Simek Cc: "Edgar E. Iglesias" , Rob Herring , Edgar Iglesias , linux-arm-kernel , Soren Brinkmann , "devicetree@vger.kernel.org" , monstr@monstr.eu, Linux Kernel Mailing List , Mark Rutland Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1473 Lines: 44 On Mon, Aug 14, 2017 at 8:47 AM, Michal Simek wrote: > On 11.8.2017 15:54, Edgar E. Iglesias wrote: >> On Fri, Aug 11, 2017 at 02:58:03PM +0200, Michal Simek wrote: >>> Hi Rob, +Edgar, >>> >>> On 10.8.2017 21:10, Rob Herring wrote: >>>> On Fri, Aug 04, 2017 at 03:45:30PM +0200, Michal Simek wrote: >>>>> From: Soren Brinkmann >>>>> >>>>> Document the DT bindings for the Zynq UltraScale+ PM Firmware. [...] >>>>> + - method: The method of calling the PM-API firmware layer. >>>>> + Permitted values are: >>>>> + - "smc" : To be used in configurations without a hypervisor >>>>> + - "hvc" : To be used when hypervisor is present >>>> >>>> Do you really use both? >>>> >>> >>> SMCs definitely yes. >>> >>> Interface was designed in that way and I don't know if people are using >>> it or not. >>> >>> Not sure if Xen is blocking SMCs. I know we have discussed it but not >>> sure if this is enabled by default or only for certain configurations. >>> Also not sure if xen contains handler for hvc. >>> Edgar: Do you know? >> >> We have patches for Xen that implement a power-management mediator. >> That implementation handles PM calls over both SMC and HVC insns. >> Patches are on the Xen mailing list. >> >> Other hypervisors may work differently. >> >> I think we should support both but I don't have a strong opinion on it. > > Rob: Are you ok with having it there? Yes. Rob