From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89A30C6379D for ; Tue, 24 Nov 2020 16:11:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54B4F2073C for ; Tue, 24 Nov 2020 16:11:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390189AbgKXQK4 (ORCPT ); Tue, 24 Nov 2020 11:10:56 -0500 Received: from foss.arm.com ([217.140.110.172]:41250 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728249AbgKXQKz (ORCPT ); Tue, 24 Nov 2020 11:10:55 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5C9411396; Tue, 24 Nov 2020 08:10:55 -0800 (PST) Received: from e123648.arm.com (unknown [10.57.29.140]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6CDD43F71F; Tue, 24 Nov 2020 08:10:53 -0800 (PST) From: Lukasz Luba To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: daniel.lezcano@linaro.org, amitk@kernel.org, Dietmar.Eggemann@arm.com, lukasz.luba@arm.com, ionela.voinescu@arm.com Subject: [PATCH v4 1/3] thermal: power allocator: change the 'k_i' coefficient estimation Date: Tue, 24 Nov 2020 16:10:23 +0000 Message-Id: <20201124161025.27694-2-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201124161025.27694-1-lukasz.luba@arm.com> References: <20201124161025.27694-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Intelligent Power Allocation (IPA) is built around the PID controller concept. The initialization code tries to setup the environment based on the information available in DT or estimate the value based on minimum power reported by each of the cooling device. The estimation will have an impact on the PID controller behaviour via the related 'k_po', 'k_pu', 'k_i' coefficients and also on the power budget calculation. This change prevents the situation when 'k_i' is relatively big compared to 'k_po' and 'k_pu' values. This might happen when the estimation for 'sustainable_power' returned small value, thus 'k_po' and 'k_pu' are small. Signed-off-by: Lukasz Luba --- drivers/thermal/gov_power_allocator.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index b29e21c56a4f..2e20085ed217 100644 --- a/drivers/thermal/gov_power_allocator.c +++ b/drivers/thermal/gov_power_allocator.c @@ -134,6 +134,7 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, int ret; int switch_on_temp; u32 temperature_threshold; + s32 k_i; ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp); if (ret) @@ -159,8 +160,11 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / temperature_threshold; - if (!tz->tzp->k_i || force) - tz->tzp->k_i = int_to_frac(10) / 1000; + if (!tz->tzp->k_i || force) { + k_i = tz->tzp->k_pu / 10; + tz->tzp->k_i = k_i > 0 ? k_i : 1; + } + /* * The default for k_d and integral_cutoff is 0, so we can * leave them as they are. -- 2.17.1