From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753664AbdBUQX5 (ORCPT ); Tue, 21 Feb 2017 11:23:57 -0500 Received: from mail-it0-f67.google.com ([209.85.214.67]:35887 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751555AbdBUQXv (ORCPT ); Tue, 21 Feb 2017 11:23:51 -0500 MIME-Version: 1.0 In-Reply-To: <08c5dcf3-9d7c-33ff-f801-8f94f630f49b@arm.com> References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <1487622809-25127-4-git-send-email-geert+renesas@glider.be> <08c5dcf3-9d7c-33ff-f801-8f94f630f49b@arm.com> From: Geert Uytterhoeven Date: Tue, 21 Feb 2017 17:23:48 +0100 X-Google-Sender-Auth: 81VylLWp--4iUBkqUgWNeTlIKCs Message-ID: Subject: Re: [PATCH/RFC 3/6] drivers: firmware: psci: Implement shallow suspend mode To: Sudeep Holla Cc: Geert Uytterhoeven , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , John Stultz , Thomas Gleixner , "Rafael J . Wysocki" , Len Brown , Pavel Machek , 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 11:42 AM, Sudeep Holla wrote: > On 20/02/17 20:33, Geert Uytterhoeven 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. >> >> List the available system suspend modes: >> >> $ cat /sys/power/mem_sleep >> s2idle shallow [deep] >> >> Suspend to "shallow" mode: >> >> $ echo shallow > /sys/power/mem_sleep >> $ echo mem > /sys/power/state >> > > I don't have the links to such previous attempts handy, but we have Don't worry, I did read earlier discussions about implementing shallow mode. > more elegant alternative options(suspend-to-idle) and any such attempts > to hack around the PSCI will be NACKed. "s2idle" does not power down secondary CPU cores, so this is an improvement. "deep" may not support configured wake-up sources, which is a bug. 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 17:23:48 +0100 Message-ID: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <1487622809-25127-4-git-send-email-geert+renesas@glider.be> <08c5dcf3-9d7c-33ff-f801-8f94f630f49b@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <08c5dcf3-9d7c-33ff-f801-8f94f630f49b@arm.com> Sender: linux-renesas-soc-owner@vger.kernel.org To: Sudeep Holla Cc: Geert Uytterhoeven , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , John Stultz , Thomas Gleixner , "Rafael J . Wysocki" , Len Brown , Pavel Machek , 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 11:42 AM, Sudeep Holla wrote: > On 20/02/17 20:33, Geert Uytterhoeven 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. >> >> List the available system suspend modes: >> >> $ cat /sys/power/mem_sleep >> s2idle shallow [deep] >> >> Suspend to "shallow" mode: >> >> $ echo shallow > /sys/power/mem_sleep >> $ echo mem > /sys/power/state >> > > I don't have the links to such previous attempts handy, but we have Don't worry, I did read earlier discussions about implementing shallow mode. > more elegant alternative options(suspend-to-idle) and any such attempts > to hack around the PSCI will be NACKed. "s2idle" does not power down secondary CPU cores, so this is an improvement. "deep" may not support configured wake-up sources, which is a bug. 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 17:23:48 +0100 Subject: [PATCH/RFC 3/6] drivers: firmware: psci: Implement shallow suspend mode In-Reply-To: <08c5dcf3-9d7c-33ff-f801-8f94f630f49b@arm.com> References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <1487622809-25127-4-git-send-email-geert+renesas@glider.be> <08c5dcf3-9d7c-33ff-f801-8f94f630f49b@arm.com> 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 11:42 AM, Sudeep Holla wrote: > On 20/02/17 20:33, Geert Uytterhoeven 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. >> >> List the available system suspend modes: >> >> $ cat /sys/power/mem_sleep >> s2idle shallow [deep] >> >> Suspend to "shallow" mode: >> >> $ echo shallow > /sys/power/mem_sleep >> $ echo mem > /sys/power/state >> > > I don't have the links to such previous attempts handy, but we have Don't worry, I did read earlier discussions about implementing shallow mode. > more elegant alternative options(suspend-to-idle) and any such attempts > to hack around the PSCI will be NACKed. "s2idle" does not power down secondary CPU cores, so this is an improvement. "deep" may not support configured wake-up sources, which is a bug. 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