From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932963AbdHVNRR (ORCPT ); Tue, 22 Aug 2017 09:17:17 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:61529 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932657AbdHVNRQ (ORCPT ); Tue, 22 Aug 2017 09:17:16 -0400 From: "Rafael J. Wysocki" To: Srinivas Pandruvada Cc: lenb@kernel.org, linux-pm@vger.kernel.org, mario.limonciello@dell.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [PATCH v5] ACPI / Sleep: Check low power idle constraints for debug only Date: Tue, 22 Aug 2017 15:08:44 +0200 Message-ID: <2237482.YGg0anG1lD@aspire.rjw.lan> In-Reply-To: <1502846219-19192-1-git-send-email-srinivas.pandruvada@linux.intel.com> References: <1502846219-19192-1-git-send-email-srinivas.pandruvada@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, August 16, 2017 3:16:59 AM CEST Srinivas Pandruvada wrote: > For SoC to achieve its lowest power platform idle state a set of hardware > preconditions must be met. These preconditions or constraints can be > obtained by issuing a device specific method (_DSM) with function "1". > Refer to the document provided in the link below. > > Here during initialization (from attach() callback of LPS0 device), invoke > function 1 to get the device constraints. Each enabled constraint is > stored in a table. > > The devices in this table are used to check whether they were in required > minimum state, while entering suspend. This check is done from platform > freeze wake() callback, only when /sys/power/pm_debug_messages attribute > is non zero. > > If any constraint is not met and device is ACPI power managed then it > prints the device information to kernel logs. > > Also if debug is enabled in acpi/sleep.c, the constraint table and state > of each device on wake is dumped in kernel logs. > > Since pm_debug_messages_on setting is used as condition to check > constraints outside kernel/power/main.c, pm_debug_messages_on is changed > to a global variable. > > Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf > Signed-off-by: Srinivas Pandruvada Applied, thanks!