From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753858AbdBUQdB (ORCPT ); Tue, 21 Feb 2017 11:33:01 -0500 Received: from mail-it0-f66.google.com ([209.85.214.66]:36636 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752992AbdBUQcw (ORCPT ); Tue, 21 Feb 2017 11:32:52 -0500 MIME-Version: 1.0 In-Reply-To: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <1487622809-25127-4-git-send-email-geert+renesas@glider.be> <20170221110712.GB5021@amd> From: Geert Uytterhoeven Date: Tue, 21 Feb 2017 17:32:50 +0100 X-Google-Sender-Auth: vDtGz_SBOLBiKAoJQQx_oqo-Ito Message-ID: Subject: Re: [PATCH/RFC 3/6] drivers: firmware: psci: Implement shallow suspend mode To: Sudeep Holla Cc: Pavel Machek , Geert Uytterhoeven , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , John Stultz , Thomas Gleixner , "Rafael J . Wysocki" , Len Brown , Rob Herring , Magnus Damm , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Linux-Renesas , Linux PM list , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sudeep, On Tue, Feb 21, 2017 at 12:14 PM, Sudeep Holla wrote: > On 21/02/17 11:07, Pavel Machek wrote: >>> Enable support for "shallow" suspend mode, also known as "Standby" or >>> "Power-On Suspend". >>> >>> As secondary CPU cores are taken offline, "shallow" suspend mode saves >>> slightly more power than "s2idle", but less than "deep" suspend mode. >>> However, unlike "deep" suspend mode, "shallow" suspend mode can be used >>> regardless of the presence of support for PSCI_SYSTEM_SUSPEND, which is >>> an optional API in PSCI v1.0. >> >> If system supports "shallow" suspend, why does not PSCI implement it? > > Yes it can, and IIUC it already does on this platform with CPU_SUSPEND. > All it now needs is just to use existing "freeze" suspend mode in Linux. How can Linux know if using "deep" suspend will allow to wake-up the system according to configured wake-up sources, or not? Note that "it will not, ever" is an accepted answer. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH/RFC 3/6] drivers: firmware: psci: Implement shallow suspend mode Date: Tue, 21 Feb 2017 17:32:50 +0100 Message-ID: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <1487622809-25127-4-git-send-email-geert+renesas@glider.be> <20170221110712.GB5021@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: Sender: linux-pm-owner@vger.kernel.org To: Sudeep Holla Cc: Pavel Machek , Geert Uytterhoeven , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , John Stultz , Thomas Gleixner , "Rafael J . Wysocki" , Len Brown , Rob Herring , Magnus Damm , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Linux-Renesas , Linux PM list , "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org Hi Sudeep, On Tue, Feb 21, 2017 at 12:14 PM, Sudeep Holla wrote: > On 21/02/17 11:07, Pavel Machek wrote: >>> Enable support for "shallow" suspend mode, also known as "Standby" or >>> "Power-On Suspend". >>> >>> As secondary CPU cores are taken offline, "shallow" suspend mode saves >>> slightly more power than "s2idle", but less than "deep" suspend mode. >>> However, unlike "deep" suspend mode, "shallow" suspend mode can be used >>> regardless of the presence of support for PSCI_SYSTEM_SUSPEND, which is >>> an optional API in PSCI v1.0. >> >> If system supports "shallow" suspend, why does not PSCI implement it? > > Yes it can, and IIUC it already does on this platform with CPU_SUSPEND. > All it now needs is just to use existing "freeze" suspend mode in Linux. How can Linux know if using "deep" suspend will allow to wake-up the system according to configured wake-up sources, or not? Note that "it will not, ever" is an accepted answer. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: geert@linux-m68k.org (Geert Uytterhoeven) Date: Tue, 21 Feb 2017 17:32:50 +0100 Subject: [PATCH/RFC 3/6] drivers: firmware: psci: Implement shallow suspend mode In-Reply-To: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <1487622809-25127-4-git-send-email-geert+renesas@glider.be> <20170221110712.GB5021@amd> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Sudeep, On Tue, Feb 21, 2017 at 12:14 PM, Sudeep Holla wrote: > On 21/02/17 11:07, Pavel Machek wrote: >>> Enable support for "shallow" suspend mode, also known as "Standby" or >>> "Power-On Suspend". >>> >>> As secondary CPU cores are taken offline, "shallow" suspend mode saves >>> slightly more power than "s2idle", but less than "deep" suspend mode. >>> However, unlike "deep" suspend mode, "shallow" suspend mode can be used >>> regardless of the presence of support for PSCI_SYSTEM_SUSPEND, which is >>> an optional API in PSCI v1.0. >> >> If system supports "shallow" suspend, why does not PSCI implement it? > > Yes it can, and IIUC it already does on this platform with CPU_SUSPEND. > All it now needs is just to use existing "freeze" suspend mode in Linux. How can Linux know if using "deep" suspend will allow to wake-up the system according to configured wake-up sources, or not? Note that "it will not, ever" is an accepted answer. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds