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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5C3F1F513F4 for ; Fri, 6 Mar 2026 04:08:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=qRN4R8ydX4bHhNIuCgWlwTOtwizlKM6MCX8177HggnY=; b=kGyaw/0yF4lfiNINsyfWZGfcRa 69QwCa39vcdNCxv+I+4SmE4kh2JKGsoxB/gFrkVBWB1DS9Hy0TJwU98HyW9ljrsLuX9tnLLk46F2S E91Lfn8NtuhU/u00npPTphnx1v+ZpUWQaVXb8/5h5vA08NVFqs+9Kik1uuHH6BN0kPTtKUGxpNH8+ o8dUPlShc7sECGXPUw29z1264gIqOK4faGVMHPuakxccG2ZU2VvhmngVXMxbzcrruV3qG3MeAZrhw uNf1ZBuewLYS/BQUFKqKBcdbcEEARcD9zeZQVd6AAx4RddNo2DiQD7t5b1/LN3iJV+I7PmsUsQeVP ZFN1dkIw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vyMUZ-00000002zZ1-2XNB; Fri, 06 Mar 2026 04:08:47 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vyMUX-00000002zYm-3sfw; Fri, 06 Mar 2026 04:08:45 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id A01AE60018; Fri, 6 Mar 2026 04:08:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27164C4CEF7; Fri, 6 Mar 2026 04:08:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772770124; bh=2PV8N8MDNTOIV9r2E8N///4zaacKBlEGosc7fKjx3Ks=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tmxtOwOhkKzMEj+l4kjbSGSuOg7q9bHOnXBu+LsMBBRZo8TYzqttB3ZNEaxUX6m28 igTKTyxj3cQRvmuvLaRvYHJw+nt5jnTp7wXY0m0QnUm8yu091nD34pKpvnSAIgAccP uGSdwoFTKF/uACYkjMzjVw6CB1kQiTp6zQpGjdX/pX/SAiO6clV+uztpVXo+ZntuvP agHB0e4n7vRHhepIRQFJ6LpOgMB2Be8yKcppfPk6Jvp/CpYr9ZeC46kfu4CB73QFsA XOow38xou8xbkFJRc/SM44AAtfsLR94yXX8ZlwSrgYBRZWXksYlLpcZSRrXYMwN8DN J+X+j28Gsr7mQ== Date: Thu, 5 Mar 2026 18:08:43 -1000 From: Tejun Heo To: Krzysztof Kozlowski Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Jonathan Corbet , Shuah Khan , Lai Jiangshan , Tobias Schrammm , Sebastian Reichel , Andy Shevchenko , Dan Carpenter , Krzysztof Kozlowski , Lee Jones , Dzmitry Sankouski , Matthias Brugger , AngeloGioacchino Del Regno , Benson Leung , Tzung-Bi Shih , Matti Vaittinen , driver-core@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Sebastian Reichel , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, chrome-platform@lists.linux.dev Subject: Re: [PATCH v2 01/10] workqueue: devres: Add device-managed allocate workqueue Message-ID: References: <20260305-workqueue-devm-v2-0-66a38741c652@oss.qualcomm.com> <20260305-workqueue-devm-v2-1-66a38741c652@oss.qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260305-workqueue-devm-v2-1-66a38741c652@oss.qualcomm.com> X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Thu, Mar 05, 2026 at 10:45:40PM +0100, Krzysztof Kozlowski wrote: > Add a Resource-managed version of alloc_workqueue() to fix common > problem of drivers mixing devm() calls with destroy_workqueue. Such > naive and discouraged driver approach leads to difficult to debug bugs > when the driver: > > 1. Allocates workqueue in standard way and destroys it in driver > remove() callback, > 2. Sets work struct with devm_work_autocancel(), > 3. Registers interrupt handler with devm_request_threaded_irq(). > > Which leads to following unbind/removal path: > > 1. destroy_workqueue() via driver remove(), > Any interrupt coming now would still execute the interrupt handler, > which queues work on destroyed workqueue. > 2. devm_irq_release(), > 3. devm_work_drop() -> cancel_work_sync() on destroyed workqueue. > > devm_alloc_workqueue() has two benefits: > 1. Solves above problem of mix-and-match devres and non-devres code in > driver, > 2. Simplify any sane drivers which were correctly using > alloc_workqueue() + devm_add_action_or_reset(). > > Signed-off-by: Krzysztof Kozlowski Acked-by: Tejun Heo Please let me know how you wanna route the patch. Thanks. -- tejun