From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 33119314B8E for ; Wed, 15 Oct 2025 07:16:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760512617; cv=none; b=cdlGQEj8snovN0USEA8QpDPRXKKDEm1Qsw1zqJJ2EB14R6dDICHkUno4HI+1VyGAgEF8o08tgikWEpMTVU66TNwKYclv4cOBRrtsVDhrN5Olf19Sxn8rYKzMGN6Hjzbe1/Q57Qw9+sj2BMa0NSTl/2+lNK24UTkFVLWuNIb082E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760512617; c=relaxed/simple; bh=V+iummctOk7jK5ncxqpIAFHCOqEzYZrN3poJkv4LWj8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZcGL8jAasnuaynaOGMHcwqtCzrJBkNw5Cm9u1Mk2vlTO456XYdEkBBv3NWzLPXnFzbZpRasKUCKvZBZko6VjIxGFhWWmqUSfTxvQjJmfA+u5DBLJMUgs40vWGwPCh8T98jKPiAclyruwS9WYlxoB7Udjibk7fDULQQYDgDS14Oo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=wF0zbsB9; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="wF0zbsB9" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id A22D04E410C3; Wed, 15 Oct 2025 07:16:53 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 736A4606F9; Wed, 15 Oct 2025 07:16:53 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 482E7102F22BC; Wed, 15 Oct 2025 09:16:39 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1760512610; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=X9BnZFYvaDaBrjNH0qmNsDFsMFzgh2toDVIGE3HodzQ=; b=wF0zbsB96L/vcny88gPyvRaUxpZHC7jTsCEDP+BpIT8kJL3wJIhltkX+1JGG5B7Y4ZkccH h79djKbNIuesipGeAwPzhK1XMKW9hBTvwxDVTGfpqDKhn6pNGH/UQwT7iH20TqLjtu2LOd opFdGQ3nnsgWi1PX/mJXptY0L9QodswKu4zcx3Bx+F9E48du48h11KAotI9mympvFACGal 20rGBi1mMQTY7F43DdoBAToQ6DADEWms3t+RO3WkGp4pQfnQDp50z7tn5xme6S8cwzSOrl 69SZFRxPgC7NTWf91rZWMIZE3MEBiEBoKNIQFW1Dp2PIwig3bweaMlFTUelUqA== From: Herve Codina To: Andrew Lunn , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Michael Turquette , Stephen Boyd , Andi Shyti , Wolfram Sang , Peter Rosin , Arnd Bergmann , Herve Codina , Saravana Kannan , Bjorn Helgaas , Charles Keepax , Richard Fitzgerald , David Rhodes , Linus Walleij , Ulf Hansson , Mark Brown , Andy Shevchenko , Daniel Scally , Heikki Krogerus , Sakari Ailus , Len Brown , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , Ira Weiny , Dan Williams , Geert Uytterhoeven Cc: Wolfram Sang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-i2c@vger.kernel.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, patches@opensource.cirrus.com, linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org, linux-spi@vger.kernel.org, linux-acpi@vger.kernel.org, linux-cxl@vger.kernel.org, Allan Nielsen , Horatiu Vultur , Steen Hegelund , Luca Ceresoli , Thomas Petazzoni Subject: [PATCH v4 04/29] driver core: Avoid warning when removing a device while its supplier is unbinding Date: Wed, 15 Oct 2025 09:13:51 +0200 Message-ID: <20251015071420.1173068-5-herve.codina@bootlin.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251015071420.1173068-1-herve.codina@bootlin.com> References: <20251015071420.1173068-1-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 During driver removal, the following warning can appear: WARNING: CPU: 1 PID: 139 at drivers/base/core.c:1497 __device_links_no_driver+0xcc/0xfc ... Call trace: __device_links_no_driver+0xcc/0xfc (P) device_links_driver_cleanup+0xa8/0xf0 device_release_driver_internal+0x208/0x23c device_links_unbind_consumers+0xe0/0x108 device_release_driver_internal+0xec/0x23c device_links_unbind_consumers+0xe0/0x108 device_release_driver_internal+0xec/0x23c device_links_unbind_consumers+0xe0/0x108 device_release_driver_internal+0xec/0x23c driver_detach+0xa0/0x12c bus_remove_driver+0x6c/0xbc driver_unregister+0x30/0x60 pci_unregister_driver+0x20/0x9c lan966x_pci_driver_exit+0x18/0xa90 [lan966x_pci] This warning is triggered when a consumer is removed because the links status of its supplier is not DL_DEV_DRIVER_BOUND and the link flag DL_FLAG_SYNC_STATE_ONLY is not set. The topology in terms of consumers/suppliers used was the following (consumer ---> supplier): i2c -----------> OIC ----> PCI device | ^ | | +---> pinctrl ---+ When the PCI device is removed, the OIC (interrupt controller) has to be removed. In order to remove the OIC, pinctrl and i2c need to be removed and to remove pinctrl, i2c need to be removed. The removal order is: 1) i2c 2) pinctrl 3) OIC 4) PCI device In details, the removal sequence is the following (with 0000:01:00.0 the PCI device): driver_detach: call device_release_driver_internal(0000:01:00.0)... device_links_busy(0000:01:00.0): links->status = DL_DEV_UNBINDING device_links_unbind_consumers(0000:01:00.0): 0000:01:00.0--oic link->status = DL_STATE_SUPPLIER_UNBIND call device_release_driver_internal(oic)... device_links_busy(oic): links->status = DL_DEV_UNBINDING device_links_unbind_consumers(oic): oic--pinctrl link->status = DL_STATE_SUPPLIER_UNBIND call device_release_driver_internal(pinctrl)... device_links_busy(pinctrl): links->status = DL_DEV_UNBINDING device_links_unbind_consumers(pinctrl): pinctrl--i2c link->status = DL_STATE_SUPPLIER_UNBIND call device_release_driver_internal(i2c)... device_links_busy(i2c): links->status = DL_DEV_UNBINDING __device_links_no_driver(i2c)... pinctrl--i2c link->status is DL_STATE_SUPPLIER_UNBIND oic--i2c link->status is DL_STATE_ACTIVE oic--i2c link->supplier->links.status is DL_DEV_UNBINDING The warning is triggered by the i2c removal because the OIC (supplier) links status is not DL_DEV_DRIVER_BOUND. Its links status is indeed set to DL_DEV_UNBINDING. It is perfectly legit to have the links status set to DL_DEV_UNBINDING in that case. Indeed we had started to unbind the OIC which triggered the consumer unbinding and didn't finish yet when the i2c is unbound. Avoid the warning when the supplier links status is set to DL_DEV_UNBINDING and thus support this removal sequence without any warnings. Signed-off-by: Herve Codina Reviewed-by: Rafael J. Wysocki Reviewed-by: Saravana Kannan --- drivers/base/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index cf157066499b..3e81b1914ce5 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1491,7 +1491,8 @@ static void __device_links_no_driver(struct device *dev) if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { WRITE_ONCE(link->status, DL_STATE_AVAILABLE); } else { - WARN_ON(!device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)); + WARN_ON(link->supplier->links.status != DL_DEV_UNBINDING && + !device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)); WRITE_ONCE(link->status, DL_STATE_DORMANT); } } -- 2.51.0