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 A626834FF4D; Mon, 23 Feb 2026 11:52:21 +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=1771847541; cv=none; b=ND6g6UwGUkpwMq+v2B0qzf4q4QC8pQIN8IAp8SwVpze7j711DGwFhAwNXd++UpL8BYyemBaav7pK4i7FMDj56b8KVqZKlS4dcHeAan6wNLk4Jy5POhB5JWYX1qKauXtga4KrWLyTvU/AYTeB4itDyJWuXYNxInMf0NOZv25tKIg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771847541; c=relaxed/simple; bh=roYpKDMhh6cZ9yMZGMqqIqsHrMiwIf+FyPju6t+JsNk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=EeZhU1rfTLPL4nDRySL2zGhvqb1jA/Uf0ENwPWdoeZM0ShWhOgJYUgGpmP7rG6uY8MiTHB/5rhLRMSs9ybc0rN1EmwMPC5ADy+5U9uXuNpq4HTtT9zM4fDqnww7PwewsP/Q7hcDGLgcdeNYWOMFCr7AUvRYT4khkO/3XbFtdUiU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lwVm9Hfo; 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="lwVm9Hfo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03CFFC116D0; Mon, 23 Feb 2026 11:52:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771847541; bh=roYpKDMhh6cZ9yMZGMqqIqsHrMiwIf+FyPju6t+JsNk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=lwVm9HfohJudq8qLJ8kGaEf5+GmCGQdn3IxLVTtdB0l5TJ7Pp3jpG6gcMPHFrCGSq 4BX0U+zIUMlnjCOyMdxQnajlDOscDkCWnjj2FqUxf4U+FZAROhti967yt9DFZB0fJS s3KBsW/7/BvfEzWx3BqiWSHa0ckmdt4q6boEwiqCXtjHJRpcPDi58TE51OJDfXnopZ lgzSWnrmXBYp1z79BRCcIxt1jiTnTTNaX4Wbit3b1MPn40x3Ayf0mTFRCASA++bmkE /xlA3kenzLI750wvol/nnViv2WQAK+kThLc/rB0WiAU0Tk99A7ORnmBOJCFFBkuPno a3GGGIODSo1lQ== Message-ID: <9dd377f6-3565-4c0c-8c98-1b5ac4982f5b@kernel.org> Date: Mon, 23 Feb 2026 12:52:14 +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? > Answering with update: I don't think this should go to devm-helpers.h. The definition is in workqueue.c, thus the declaration should be in corresponding header. It's logical and consistent. Otherwise, I could move it entirely - definition and declaration - to devm-helpers.h, but then the release (devm_destroy_workqueue()) will be essentially exported to everyone through the header. So kind of conflicting choices. Best regards, Krzysztof