From patchwork Tue Mar 23 13:49:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Vaittinen, Matti" X-Patchwork-Id: 12157977 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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 AF819C433DB for ; Tue, 23 Mar 2021 13:50:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77A13619B3 for ; Tue, 23 Mar 2021 13:50:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230449AbhCWNtn (ORCPT ); Tue, 23 Mar 2021 09:49:43 -0400 Received: from mail-lj1-f175.google.com ([209.85.208.175]:42655 "EHLO mail-lj1-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230078AbhCWNtb (ORCPT ); Tue, 23 Mar 2021 09:49:31 -0400 Received: by mail-lj1-f175.google.com with SMTP id 184so25677965ljf.9; Tue, 23 Mar 2021 06:49:30 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=mFWNgc1FW5QaVvw/wsJgMcMblBrOgtay4PdG9vIWiv0=; b=FvVyVQVsLQoE4k5/J1DM8EN5nXrnEwwGou+LREOttVV++wOuq/w19+yy6kvngoIypl b2hwIJqaId0vkehPrAKTy3mmSYFPjdQsLzTD+O3b8SJOKWhz7/ehXJBAduY63o/xCXKF ctl9Bt7CHW66JZ2Lk/sFc+8M762u/3aFRA0hhhgWKxAw8WF8gAIZBRawgRKvS0LFKuxO jb5oloSGf0EE0N4VpkeO4qYcZEdWrqQQfmN8Kparl2f+w6ZQ6d5xAEBZiwTsTb/onUvW O38yvciw4SEqBawanEGzOCOT5KPhBfubQZukp1IvM3p0Pj+mncdXDMIe3P/XHqzJN3f4 /6Ug== X-Gm-Message-State: AOAM5321c8uPfPcT0FIM4pKrkY04Hx2jMHvLvmOAjLAm7Dm3ayjPBn+K ykfyp6vFGVJLM2rNWf1jg+E= X-Google-Smtp-Source: ABdhPJzCrYWUnFHopBuwoTQCnEVSaGjYd/0HCeCkwyJiUJo8kLjKK212FjDHsyFBrcl4geyYwMfp3w== X-Received: by 2002:a2e:9b4a:: with SMTP id o10mr3196706ljj.485.1616507369334; Tue, 23 Mar 2021 06:49:29 -0700 (PDT) Received: from localhost.localdomain (dc7vkhyyyyyyyyyyyyyby-3.rev.dnainternet.fi. [2001:14ba:16e2:8300::2]) by smtp.gmail.com with ESMTPSA id i30sm1079430lfj.206.2021.03.23.06.49.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Mar 2021 06:49:28 -0700 (PDT) Date: Tue, 23 Mar 2021 15:49:21 +0200 From: Matti Vaittinen To: Matti Vaittinen , Matti Vaittinen Cc: MyungJoo Ham , Chanwoo Choi , Andy Gross , Bjorn Andersson , Jean Delvare , Guenter Roeck , Hans de Goede , Mark Gross , Sebastian Reichel , Chen-Yu Tsai , Liam Girdwood , Mark Brown , Wim Van Sebroeck , Matti Vaittinen , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-hwmon@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-pm@vger.kernel.org, linux-watchdog@vger.kernel.org Subject: [PATCH v3 0/8] Add managed version of delayed work init Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org It's not rare that device drivers need delayed work. It's not rare that this work needs driver's data. Often this means that driver must ensure the work is not queued when driver is detached. Often it is done by ensuring new work is not added and then calling cancel_delayed_work_sync() at remove(). In many cases this may also require cleanup at probe error path - which is easy to forget. Also the "by ensuring new work is not added" has a gotcha. It is not strange to see devm managed IRQs scheduling (delayed) work. Mixing this with manua wq clean-up is hard to do correctly because the devm is likely to free the IRQ only after the remove() is ran. So manual wq cancellation and devm-based IRQ management do not mix well - there is a short(?) time-window after the wq clean-up when IRQs are still not freed and may schedule new work. When both WQs and IRQs are managed by devm things are likely to just work. WQs should be initialized before IRQs (when IRQs need to schedule work) and devm unwinds things in "FILO" order. This series implements delayed wq cancellation on top of devm and replaces the obvious cases where only thing remove call-back in a driver does is cancelling the work. There might be other cases where we could switch more than just work cancellation to use managed version and thus get rid of remove or mixed (manual and devm) resource management. The series introduces include/linux/devm-helpers.h file which hopefully works as a place where this kind of helpers can be inlined. Please see previous discussion here: RFC v1: https://lore.kernel.org/lkml/cover.1613216412.git.matti.vaittinen@fi.rohmeurope.com/ Changelog v3: - Dropped RFC as advieced by Greg. - No functional changes. Changelog RFC v2 resend: - rebased on 5.12-rc4 Changelog RFC v2: - used correct terminology ("driver detach" instead of "exit, ...") - inlined the devm_delayed_work_autocancel() in a header - added Hans as a maintainer for the new header + myself as a reviewer - used devm_add_action() instead of using plain devres_add() --- Matti Vaittinen (8): workqueue: Add resource managed version of delayed work init MAINTAINERS: Add entry for devm helpers extconn: Clean-up few drivers by using managed work init hwmon: raspberry-pi: Clean-up few drivers by using managed work init platform/x86: gpd pocket fan: Clean-up by using managed work init power: supply: Clean-up few drivers by using managed work init regulator: qcom_spmi-regulator: Clean-up by using managed work init watchdog: retu_wdt: Clean-up by using managed work init MAINTAINERS | 6 +++ drivers/extcon/extcon-gpio.c | 15 ++---- drivers/extcon/extcon-intel-int3496.c | 16 ++---- drivers/extcon/extcon-palmas.c | 17 +++---- drivers/extcon/extcon-qcom-spmi-misc.c | 17 +++---- drivers/hwmon/raspberrypi-hwmon.c | 17 +++---- drivers/platform/x86/gpd-pocket-fan.c | 17 +++---- drivers/power/supply/axp20x_usb_power.c | 15 ++---- drivers/power/supply/bq24735-charger.c | 18 +++---- drivers/power/supply/ltc2941-battery-gauge.c | 20 +++----- drivers/power/supply/sbs-battery.c | 16 ++---- drivers/regulator/qcom_spmi-regulator.c | 34 +++---------- drivers/watchdog/retu_wdt.c | 22 +++----- include/linux/devm-helpers.h | 53 ++++++++++++++++++++ 14 files changed, 128 insertions(+), 155 deletions(-) create mode 100644 include/linux/devm-helpers.h base-commit: 0d02ec6b3136c73c09e7859f0d0e4e2c4c07b49b