From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B838735BDB7; Mon, 23 Feb 2026 10:18:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771841929; cv=none; b=F2ZtYKMJ2zavCVRg5izMcWEO31hbvhyvX1JkB5yHd80m8j1bnMyZv9bWrvtygthHoN8wF3qo7yVVm0f5jPX4iZMC2x1AUYmDpX7ePGtXA27BICvDWnZf6DpuUQqB6j6W36N3kDqj9GtjmJwugxvoMEl8InN4OrGiQer3KOF2OoA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771841929; c=relaxed/simple; bh=vA/9bw48qeJHcc7T2p9LnhnwiLZGKOxWqrYOZe/cSMI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RSiTSgXnSJj06cTPDkhRNRkC5YBv+6PE4gL2sb+8OCGuOweyI/EDsetzDmU5qPk+cl/Ra/wzuHoJEUcyG6ChFO7UVCvCZxwj+5qZ9BHm9TE/Tg8H+vpXK4533add9lSF3ngp9tHgoctB3yBxp5MEWPuZ2xA6TuB7P3bg5+6wqtg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=He+iLFkm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="He+iLFkm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F194CC116D0; Mon, 23 Feb 2026 10:18:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771841929; bh=vA/9bw48qeJHcc7T2p9LnhnwiLZGKOxWqrYOZe/cSMI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=He+iLFkmhb10PCtcvbiCcBZxvFQkflyWF/MqYm6W1KnBjkIDCOk8i3bjnYqAxGnTG Es3Xc+FranQrXtoOF/7h/jkvvGGxvGBP++VUFvMOLRLfvxlD/OgyPNsByOeLN2ZqqN c2aFIhcO1QamPCYHtg1lwIqPpiDhBPvFfRV8LUZC5FdmDp0r5B+2WBZPSsygXtESgb iJL0SqGm+LZMU62gG6cCfdCIx+9TQFsCNaC058s4v8xZqw6+RTqHY+c5uMbMMuawfa dh/UOLPTBnrt0cLjq217cjqqkUFwJqPB0yiBNjAE/b9GVLop5GsDuqesExhpS6pCUg q+9jFcWGfqjxA== Message-ID: <534a9d0f-600e-4162-a48c-f9797241dacd@kernel.org> Date: Mon, 23 Feb 2026 11:18:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/9] workqueue: devres: Add device-managed allocate workqueue To: Andy Shevchenko , Krzysztof Kozlowski Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Jonathan Corbet , Shuah Khan , Tejun Heo , Lai Jiangshan , Tobias Schrammm , Sebastian Reichel , Dan Carpenter , Lee Jones , Dzmitry Sankouski , Matthias Brugger , AngeloGioacchino Del Regno , Benson Leung , Tzung-Bi Shih , 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 References: <20260223-workqueue-devm-v1-0-10b3a6087586@oss.qualcomm.com> <20260223-workqueue-devm-v1-1-10b3a6087586@oss.qualcomm.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 23/02/2026 09:56, Andy Shevchenko wrote: > On Mon, Feb 23, 2026 at 08:27:29AM +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(). > >> include/linux/workqueue.h | 32 ++++++++++++++++++++++++ >> kernel/workqueue.c | 32 ++++++++++++++++++++++++ > > Hmm... We have devm-helpers.h. Why the new one is in workqueue.h? > Can we have some consistency here? No problem, I can move it there. > > ... > >> + ptr = devres_alloc(devm_destroy_workqueue, sizeof(*ptr), GFP_KERNEL); >> + if (!ptr) >> + return NULL; >> + >> + va_start(args, max_active); >> + wq = alloc_workqueue(fmt, flags, max_active, args); >> + va_end(args); >> + if (wq) { >> + *ptr = wq; >> + devres_add(dev, ptr); >> + } else { >> + devres_free(ptr); >> + } > > Why not using devm_add_action_or_reset()? Where? Here? How the code would be simpler, exactly? > > ... > >> +void devm_destroy_workqueue(struct device *dev, void *res) >> +{ >> + destroy_workqueue(*(struct workqueue_struct **)res); >> +} >> +EXPORT_SYMBOL_GPL(devm_destroy_workqueue); > > Is this going to be used? It is not used in this patchset, but most of devm-allocators have the cleanup. Best regards, Krzysztof