From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751531AbdBWPez (ORCPT ); Thu, 23 Feb 2017 10:34:55 -0500 Received: from mail-it0-f65.google.com ([209.85.214.65]:34485 "EHLO mail-it0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751049AbdBWPew (ORCPT ); Thu, 23 Feb 2017 10:34:52 -0500 MIME-Version: 1.0 In-Reply-To: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <94167d3a-e005-3af0-d290-a1086684d570@arm.com> <3c8b3f2d-8604-f999-4208-a82f171b64f2@arm.com> <1975396.x0czmkNPOW@aspire.rjw.lan> <35840771-e16f-d6fe-3a89-1b3f51f4a8f3@arm.com> From: Geert Uytterhoeven Date: Thu, 23 Feb 2017 16:34:50 +0100 X-Google-Sender-Auth: PuMtOyCctvTGN3o5w9mXf2nVjes Message-ID: Subject: Re: [PATCH/RFC 0/6] PSCI: Fix non-PMIC wake-up if SYSTEM_SUSPEND cuts power To: Sudeep Holla Cc: "Rafael J. Wysocki" , Geert Uytterhoeven , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , John Stultz , Thomas Gleixner , 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 Thu, Feb 23, 2017 at 4:26 PM, Geert Uytterhoeven wrote: > On Wed, Feb 22, 2017 at 3:32 PM, Sudeep Holla wrote: >> On 22/02/17 13:38, Geert Uytterhoeven wrote: >>> On Wed, Feb 22, 2017 at 12:03 PM, Sudeep Holla wrote: >>> 4. Patch 3/6 adds a new "shallow" state, as it allows to save more >>> power (the difference may be due to suboptimal cpuidle platform support on R-Car Gen3, though), >> >> Why can't you do that in s2idle mode. Please give me the difference >> between your shallow state and s2idle state, not just power numbers >> but the actual state of CPUs and the devices in the system. > > From the Linux side, there's not much difference, except that the secondary > CPU cores are disabled. As that is handled by PSCI, the difference may be > in the PSCI implementation. I will have to check that... > > On these SoCs, the individual CPU cores and the SCU/L2 are in separate > (nested) power areas. Perhaps these power areas are turned off when > disabling the CPU cores, but not when suspending them. BTW, I don't care much about the extra state. >>> E.g. on non-PSCI platforms with an Ethernet driver that supports >>> Wake-on-LAN, I can do: >>> >>> ethtool -s eth0 wol g >>> echo mem > /sys/power/state >>> >>> and be sure that the system can be woken up by sending a WoL MagicPacket. >> >> Still possible with s2idle if CPU_SUSPEND is correctly implemented by >> the platform. > > Sure. But not automatic, as it needs fiddling with mem_sleep. I do care about this, as it affects user experience. 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 0/6] PSCI: Fix non-PMIC wake-up if SYSTEM_SUSPEND cuts power Date: Thu, 23 Feb 2017 16:34:50 +0100 Message-ID: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <94167d3a-e005-3af0-d290-a1086684d570@arm.com> <3c8b3f2d-8604-f999-4208-a82f171b64f2@arm.com> <1975396.x0czmkNPOW@aspire.rjw.lan> <35840771-e16f-d6fe-3a89-1b3f51f4a8f3@arm.com> 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: "Rafael J. Wysocki" , Geert Uytterhoeven , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , John Stultz , Thomas Gleixner , 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 Thu, Feb 23, 2017 at 4:26 PM, Geert Uytterhoeven wrote: > On Wed, Feb 22, 2017 at 3:32 PM, Sudeep Holla wrote: >> On 22/02/17 13:38, Geert Uytterhoeven wrote: >>> On Wed, Feb 22, 2017 at 12:03 PM, Sudeep Holla wrote: >>> 4. Patch 3/6 adds a new "shallow" state, as it allows to save more >>> power (the difference may be due to suboptimal cpuidle platform support on R-Car Gen3, though), >> >> Why can't you do that in s2idle mode. Please give me the difference >> between your shallow state and s2idle state, not just power numbers >> but the actual state of CPUs and the devices in the system. > > From the Linux side, there's not much difference, except that the secondary > CPU cores are disabled. As that is handled by PSCI, the difference may be > in the PSCI implementation. I will have to check that... > > On these SoCs, the individual CPU cores and the SCU/L2 are in separate > (nested) power areas. Perhaps these power areas are turned off when > disabling the CPU cores, but not when suspending them. BTW, I don't care much about the extra state. >>> E.g. on non-PSCI platforms with an Ethernet driver that supports >>> Wake-on-LAN, I can do: >>> >>> ethtool -s eth0 wol g >>> echo mem > /sys/power/state >>> >>> and be sure that the system can be woken up by sending a WoL MagicPacket. >> >> Still possible with s2idle if CPU_SUSPEND is correctly implemented by >> the platform. > > Sure. But not automatic, as it needs fiddling with mem_sleep. I do care about this, as it affects user experience. 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: Thu, 23 Feb 2017 16:34:50 +0100 Subject: [PATCH/RFC 0/6] PSCI: Fix non-PMIC wake-up if SYSTEM_SUSPEND cuts power In-Reply-To: References: <1487622809-25127-1-git-send-email-geert+renesas@glider.be> <94167d3a-e005-3af0-d290-a1086684d570@arm.com> <3c8b3f2d-8604-f999-4208-a82f171b64f2@arm.com> <1975396.x0czmkNPOW@aspire.rjw.lan> <35840771-e16f-d6fe-3a89-1b3f51f4a8f3@arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Sudeep, On Thu, Feb 23, 2017 at 4:26 PM, Geert Uytterhoeven wrote: > On Wed, Feb 22, 2017 at 3:32 PM, Sudeep Holla wrote: >> On 22/02/17 13:38, Geert Uytterhoeven wrote: >>> On Wed, Feb 22, 2017 at 12:03 PM, Sudeep Holla wrote: >>> 4. Patch 3/6 adds a new "shallow" state, as it allows to save more >>> power (the difference may be due to suboptimal cpuidle platform support on R-Car Gen3, though), >> >> Why can't you do that in s2idle mode. Please give me the difference >> between your shallow state and s2idle state, not just power numbers >> but the actual state of CPUs and the devices in the system. > > From the Linux side, there's not much difference, except that the secondary > CPU cores are disabled. As that is handled by PSCI, the difference may be > in the PSCI implementation. I will have to check that... > > On these SoCs, the individual CPU cores and the SCU/L2 are in separate > (nested) power areas. Perhaps these power areas are turned off when > disabling the CPU cores, but not when suspending them. BTW, I don't care much about the extra state. >>> E.g. on non-PSCI platforms with an Ethernet driver that supports >>> Wake-on-LAN, I can do: >>> >>> ethtool -s eth0 wol g >>> echo mem > /sys/power/state >>> >>> and be sure that the system can be woken up by sending a WoL MagicPacket. >> >> Still possible with s2idle if CPU_SUSPEND is correctly implemented by >> the platform. > > Sure. But not automatic, as it needs fiddling with mem_sleep. I do care about this, as it affects user experience. 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