From patchwork Wed Aug 26 13:26:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Javi Merino X-Patchwork-Id: 7077191 X-Patchwork-Delegate: rui.zhang@intel.com Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3501FC05AC for ; Wed, 26 Aug 2015 13:27:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 187A12092C for ; Wed, 26 Aug 2015 13:27:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC38320932 for ; Wed, 26 Aug 2015 13:27:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756161AbbHZN1Z (ORCPT ); Wed, 26 Aug 2015 09:27:25 -0400 Received: from foss.arm.com ([217.140.101.70]:45135 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbbHZN1Y (ORCPT ); Wed, 26 Aug 2015 09:27:24 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A326E3DA; Wed, 26 Aug 2015 06:27:09 -0700 (PDT) Received: from e104805.cambridge.arm.com (e104805.cambridge.arm.com [10.2.131.190]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 54B6D3F59B; Wed, 26 Aug 2015 06:27:22 -0700 (PDT) From: Javi Merino To: linux-pm@vger.kernel.org Cc: dmitry.torokhov@gmail.com, cywang@chromium.org, linux-kernel@vger.kernel.org, punit.agrawal@arm.com, djkurtz@chromium.org, edubezval@gmail.com, Javi Merino , Zhang Rui Subject: [PATCH v4 3/5] thermal: power_allocator: relax the requirement of two passive trip points Date: Wed, 26 Aug 2015 14:26:42 +0100 Message-Id: <1440595604-27197-4-git-send-email-javi.merino@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1440595604-27197-1-git-send-email-javi.merino@arm.com> References: <1439833008-26440-1-git-send-email-javi.merino@arm.com> <1440595604-27197-1-git-send-email-javi.merino@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The power allocator governor currently requires that the thermal zone has at least two passive trip points. If there aren't, the governor refuses to bind to the thermal zone. This commit relaxes that requirement. Now the governor will bind to all thermal zones regardless of how many trip points they have. Cc: Zhang Rui Cc: Eduardo Valentin Signed-off-by: Javi Merino --- Documentation/thermal/power_allocator.txt | 2 +- drivers/thermal/power_allocator.c | 96 +++++++++++++++++-------------- 2 files changed, 53 insertions(+), 45 deletions(-) diff --git a/Documentation/thermal/power_allocator.txt b/Documentation/thermal/power_allocator.txt index c3797b529991..a1ce2235f121 100644 --- a/Documentation/thermal/power_allocator.txt +++ b/Documentation/thermal/power_allocator.txt @@ -4,7 +4,7 @@ Power allocator governor tunables Trip points ----------- -The governor requires the following two passive trip points: +The governor works optimally with the following two passive trip points: 1. "switch on" trip point: temperature above which the governor control loop starts operating. This is the first passive trip diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c index eae8a5ae794a..2dfb8ade4d1b 100644 --- a/drivers/thermal/power_allocator.c +++ b/drivers/thermal/power_allocator.c @@ -24,6 +24,8 @@ #include "thermal_core.h" +#define INVALID_TRIP -1 + #define FRAC_BITS 10 #define int_to_frac(x) ((x) << FRAC_BITS) #define frac_to_int(x) ((x) >> FRAC_BITS) @@ -61,6 +63,8 @@ static inline s64 div_frac(s64 x, s64 y) * Used to calculate the derivative term. * @trip_switch_on: first passive trip point of the thermal zone. The * governor switches on when this trip point is crossed. + * If the thermal zone only has one passive trip point, + * @trip_switch_on should be INVALID_TRIP. * @trip_max_desired_temperature: last passive trip point of the thermal * zone. The temperature we are * controlling for. @@ -435,43 +439,66 @@ unlock: return ret; } -static int get_governor_trips(struct thermal_zone_device *tz, - struct power_allocator_params *params) +/** + * get_governor_trips() - get the number of the two trip points that are key for this governor + * @tz: thermal zone to operate on + * @params: pointer to private data for this governor + * + * The power allocator governor works optimally with two trips points: + * a "switch on" trip point and a "maximum desired temperature". These + * are defined as the first and last passive trip points. + * + * If there is only one trip point, then that's considered to be the + * "maximum desired temperature" trip point and the governor is always + * on. If there are no passive or active trip points, then the + * governor won't do anything. In fact, its throttle function + * won't be called at all. + */ +static void get_governor_trips(struct thermal_zone_device *tz, + struct power_allocator_params *params) { - int i, ret, last_passive; + int i, last_active, last_passive; bool found_first_passive; found_first_passive = false; - last_passive = -1; - ret = -EINVAL; + last_active = INVALID_TRIP; + last_passive = INVALID_TRIP; for (i = 0; i < tz->trips; i++) { enum thermal_trip_type type; + int ret; ret = tz->ops->get_trip_type(tz, i, &type); - if (ret) - return ret; + if (ret) { + dev_warn(&tz->device, + "Failed to get trip point %d type: %d\n", i, + ret); + continue; + } - if (!found_first_passive) { - if (type == THERMAL_TRIP_PASSIVE) { + if (type == THERMAL_TRIP_PASSIVE) { + if (!found_first_passive) { params->trip_switch_on = i; found_first_passive = true; + } else { + last_passive = i; } - } else if (type == THERMAL_TRIP_PASSIVE) { - last_passive = i; + } else if (type == THERMAL_TRIP_ACTIVE) { + last_active = i; } else { break; } } - if (last_passive != -1) { + if (last_passive != INVALID_TRIP) { params->trip_max_desired_temperature = last_passive; - ret = 0; + } else if (found_first_passive) { + params->trip_max_desired_temperature = params->trip_switch_on; + params->trip_switch_on = INVALID_TRIP; } else { - ret = -EINVAL; + params->trip_switch_on = INVALID_TRIP; + params->trip_max_desired_temperature = last_active; } - - return ret; } static void reset_pid_controller(struct power_allocator_params *params) @@ -500,11 +527,10 @@ static void allow_maximum_power(struct thermal_zone_device *tz) * power_allocator_bind() - bind the power_allocator governor to a thermal zone * @tz: thermal zone to bind it to * - * Check that the thermal zone is valid for this governor, that is, it - * has two thermal trips. If so, initialize the PID controller - * parameters and bind it to the thermal zone. + * Initialize the PID controller parameters and bind it to the thermal + * zone. * - * Return: 0 on success, -EINVAL if the trips were invalid or -ENOMEM + * Return: 0 on success, -EINVAL if the thermal zone doesn't have tzp or -ENOMEM * if we ran out of memory. */ static int power_allocator_bind(struct thermal_zone_device *tz) @@ -523,31 +549,19 @@ static int power_allocator_bind(struct thermal_zone_device *tz) if (!tz->tzp->sustainable_power) dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); - ret = get_governor_trips(tz, params); - if (ret) { - dev_err(&tz->device, - "thermal zone %s has wrong trip setup for power allocator\n", - tz->type); - goto free; - } + get_governor_trips(tz, params); ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature, &control_temp); - if (ret) - goto free; - - estimate_controller_constants(tz, tz->tzp->sustainable_power, - params->trip_switch_on, control_temp, - false); + if (!ret) + estimate_controller_constants(tz, tz->tzp->sustainable_power, + params->trip_switch_on, + control_temp, false); reset_pid_controller(params); tz->governor_data = params; return 0; - -free: - kfree(params); - return ret; } static void power_allocator_unbind(struct thermal_zone_device *tz) @@ -578,13 +592,7 @@ static int power_allocator_throttle(struct thermal_zone_device *tz, int trip) ret = tz->ops->get_trip_temp(tz, params->trip_switch_on, &switch_on_temp); - if (ret) { - dev_warn(&tz->device, - "Failed to get switch on temperature: %d\n", ret); - return ret; - } - - if (current_temp < switch_on_temp) { + if (!ret && (current_temp < switch_on_temp)) { tz->passive = 0; reset_pid_controller(params); allow_maximum_power(tz);