From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: how to enable suspend to ram for arm-64 bits Date: Tue, 18 Oct 2016 11:59:31 +0100 Message-ID: <95484b8f-58de-3588-ac91-5ec21e66ab05@arm.com> References: <06a4f0d7-9022-578d-99e0-ddcde31ed895@arm.com> <82ddd0e1-9ecc-5e54-e8ee-86f947fc0ecd@arm.com> <20161018100002.GA4347@xo-6d-61-c0.localdomain> <20161018104539.GB15639@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from foss.arm.com ([217.140.101.70]:57240 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752107AbcJRK7e (ORCPT ); Tue, 18 Oct 2016 06:59:34 -0400 In-Reply-To: <20161018104539.GB15639@leverpostej> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Mark Rutland , Pavel Machek Cc: Sudeep Holla , yoma sophian , linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org On 18/10/16 11:45, Mark Rutland wrote: > On Tue, Oct 18, 2016 at 12:00:02PM +0200, Pavel Machek wrote: >>>> b. in arm64, if some platform has its own suspend flow, couldn't it >>>> adopts arm/match-xxx to register its own global suspend method? >>> >>> No, PSCI is highly recommended. >> >> Relying on firmware for suspend on x86 was a great disaster, lets not repeat >> that mistake. arm32 has better powermanagement than x86 ever will (see Nokia N900 >> for example) -- feel free to copy that code from arm32. > > Quite frankly, copying hundreds of lines of board-specific code > (including assembly that won't compile) is unlikely to help. > > So far arm64 requires well-defined, standard, reusable interfaces (e.g. > PSCI). That cleanly separates concerns (e.g. anyone can implement the > backend without mandatory changes to the kernel), and keeps things > maintainable. > > ARM publishes and maintains the ARM Trusted Firmware [1], which anyone > can use and build atop of. It's open source (three-clause BSD with DCO), > and accepts board ports. You can have a completely open stack, > regardless of whether part of that stack is firmware. > I think you missed to add the link[1] -- Regards, Sudeep [1] https://github.com/ARM-software/arm-trusted-firmware