Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756799AbbDOQae (ORCPT ); Wed, 15 Apr 2015 12:30:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51049 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756765AbbDOQaN (ORCPT ); Wed, 15 Apr 2015 12:30:13 -0400 Message-ID: <552E91ED.2080805@redhat.com> Date: Wed, 15 Apr 2015 10:29:33 -0600 From: Al Stone User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Catalin Marinas , Mark Rutland CC: "devicetree@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , Kumar Gala , Will Deacon , "linux-kernel@vger.kernel.org" , "arm@kernel.org" , Abhimanyu Kapur , "linux-arm-kernel@lists.infradead.org" Subject: Re: [RFC PATCH 5/5] arm64: qcom: add cpu operations References: <1428601031-5366-1-git-send-email-galak@codeaurora.org> <1428601031-5366-6-git-send-email-galak@codeaurora.org> <20150414162953.GL28709@leverpostej> <552D9A37.6070107@redhat.com> <20150415090425.GA2866@leverpostej> <20150415145350.GB22741@localhost> In-Reply-To: <20150415145350.GB22741@localhost> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2025 Lines: 50 On 04/15/2015 08:53 AM, Catalin Marinas wrote: > On Wed, Apr 15, 2015 at 10:04:25AM +0100, Mark Rutland wrote: >> On Tue, Apr 14, 2015 at 11:52:39PM +0100, Al Stone wrote: >>> On 04/14/2015 10:29 AM, Mark Rutland wrote: >>>>> diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt >>>>> index 8b9e0a9..35cabe5 100644 >>>>> --- a/Documentation/devicetree/bindings/arm/cpus.txt >>>>> +++ b/Documentation/devicetree/bindings/arm/cpus.txt >>>>> @@ -185,6 +185,8 @@ nodes to be present and contain the properties described below. >>>>> be one of: >>>>> "psci" >>>>> "spin-table" >>>> >>>> In the case of these two, there's documentation on what the OS, FW, and >>>> HW are expected to do. There's a PSCI spec, and spin-table is documented >>>> in booting.txt (which is admittedly not fantastic). >>>> [snip...] >>> >>> Perhaps a side topic, but I thought spin-table was being actively discouraged >>> for arm64. Forgive me if I missed the memo, but is that not correct? >> >> We prefer that people implement PSCI, and if they must use spin-table, >> each CPU has its own release address. >> >> However, we don't want implementation-specific mechanisms, and >> spin-table is preferable to these. > > An important aspect is that with spin-table you don't get CPU off or > suspend and some kernel functionality will be missing (kexec being one > of them). > Thanks for the clarifications. I misunderstood; I knew PSCI was preferred but somehow had it in my head that spin-table was just a non-starter. -- ciao, al ----------------------------------- Al Stone Software Engineer Red Hat, Inc. ahs3@redhat.com ----------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/