From patchwork Mon Nov 18 22:56:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 11250413 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 95968186D for ; Mon, 18 Nov 2019 22:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D55D2230C for ; Mon, 18 Nov 2019 22:56:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726769AbfKRW4v (ORCPT ); Mon, 18 Nov 2019 17:56:51 -0500 Received: from inva020.nxp.com ([92.121.34.13]:35232 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726717AbfKRW4v (ORCPT ); Mon, 18 Nov 2019 17:56:51 -0500 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 7A4851A0D95; Mon, 18 Nov 2019 23:56:49 +0100 (CET) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 6D0AD1A0427; Mon, 18 Nov 2019 23:56:49 +0100 (CET) Received: from fsr-ub1864-112.ea.freescale.net (fsr-ub1864-112.ea.freescale.net [10.171.82.98]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id F2783203BF; Mon, 18 Nov 2019 23:56:48 +0100 (CET) From: Leonard Crestez To: "Rafael J. Wysocki" , Viresh Kumar Cc: MyungJoo Ham , Kyungmin Park , Matthias Kaehlcke , Chanwoo Choi , =?utf-8?b?QXJ0dXIgxZp3aWdvxYQ=?= , Jacky Bai , Angus Ainslie , linux-pm@vger.kernel.org, linux-imx@nxp.com Subject: [PATCH v2 0/2] PM: QoS: Restore DEV_PM_QOS_MIN/MAX_FREQUENCY Date: Tue, 19 Nov 2019 00:56:41 +0200 Message-Id: X-Mailer: git-send-email 2.17.1 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Support for frequency limits in dev_pm_qos was removed when cpufreq was switched to freq_qos, this series attempts to restore it by reimplementing top of freq_qos. Previous discussion here: https://lore.kernel.org/linux-pm/VI1PR04MB7023DF47D046AEADB4E051EBEE680@VI1PR04MB7023.eurprd04.prod.outlook.com/T/#u The cpufreq core switched away because it needs contraints at the level of a "cpufreq_policy" which cover multiple cpus so dev_pm_qos coupling to struct device was not useful. Cpufreq could only use dev_pm_qos by implementing an additional layer of aggregation anyway. However the devfreq subsystem scaling is always performed for each device so dev_pm_qos is a very good match. In theory if freq_qos is extended to handle conflicting min/max values then this sharing would be useful. Right now freq_qos just ties two unrelated pm_qos aggregations for min and max freq. --- This is implemented by embeding a freq_qos_request inside dev_pm_qos_request: the data field was already an union in order to deal with flag requests. The internal freq_qos_apply is exported so that it can be called from dev_pm_qos apply_constraints. The dev_pm_qos_constraints_destroy function has no obvious equivalent in freq_qos and the whole approach of "removing requests" is somewhat dubios: request objects should be owned by consumers and the list of qos requests should be empty when the target device is deleted. Clearing the request list and would likely result in a WARN next time "update_request" is called by the requestor. Perhaps constraints_destroy should dev_warn if lists are not empty? That would be an unrelated fix for PM QoS. Changes since v1: * Don't add a leading underscore and EXPORT_SYMBOL_GPL the freq_qos_apply function; just drop the static marker. * Merged the freq_qos_apply export into the last patch. Link to v1: https://patchwork.kernel.org/cover/11212887/ Leonard Crestez (2): PM / QoS: Reorder pm_qos/freq_qos/dev_pm_qos structs PM / QoS: Restore DEV_PM_QOS_MIN/MAX_FREQUENCY drivers/base/power/qos.c | 69 +++++++++++++++++++++++++++++--- include/linux/pm_qos.h | 86 +++++++++++++++++++++++----------------- kernel/power/qos.c | 4 +- 3 files changed, 116 insertions(+), 43 deletions(-)