From nobody Thu Apr 2 17:23:03 2026 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 AB704E571; Thu, 12 Feb 2026 23:58:50 +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=1770940730; cv=none; b=Ct2EwxuNfDsI5NwTNCdMuciB+LlpdUqX3TE4+kZR6kMdE1r/EfoTWXq8T5hcUgebYmBp0t5/EomVPDMr0NVu06oX7uZuCGWrzNRADkmAO75im02DsdjxNNkR0kJFhO+9TNAGqzIjt+9415feJfax0OEK/W1S6nt1a+9g4IW7lpQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770940730; c=relaxed/simple; bh=PSdEnJFZUekkW4mxLl10WRiKBAEZWcD3+p/6dcf11yM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MWdWAdV60Q0mMKADsMsGo7Bp2kEaUKvRLGCojg8h/C4WC75C4ag+1CUl+v2lN73s8ZqyzrmuBiCeg1d+CuBipB7hW18XJPN5LiBBSs/KTZYSOGu9BQbx0OYBk9414HvY9a5jAXTkKhonOcqpUnnbnraL75UJMpGi14vEwF00kdg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U3K4/Dkh; 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="U3K4/Dkh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F1DCC4CEF7; Thu, 12 Feb 2026 23:58:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770940730; bh=PSdEnJFZUekkW4mxLl10WRiKBAEZWcD3+p/6dcf11yM=; h=From:To:Cc:Subject:Date:From; b=U3K4/DkheRkd/e/QGs2FW/3TZ47pSmFDOjL2JGU+tQR+2SKUCgjSqDeSDJp6gdTvn oZVRY7h15Qj2Y0N2615Jp056hgTSqgyOozdBa6UAnE9Tie7DTOlDEgLsuB0gWkJhhY g0JIGTr7W6KQhUdYHLzuh0LzTWRevIAGWSbsny5+L1pcop8PukOlQB1U1LipOnSb1h +ydOeyjTzlshjYzW3O9ZHbUK81x9ZUvXuQebIvvP90zP5N5DeEkMJfuBXbE9s25HP6 9zGkmhr7l/ldDqWFVeQ/31xT5eBFAmQj/x7Y96Q1IT96VmmUGBn8CY4wpj90nr1Yjt CBEgcTb1TbJng== From: Danilo Krummrich To: abelvesa@kernel.org, peng.fan@nxp.com, daniel.baluta@oss.nxp.com, mturquette@baylibre.com, sboyd@kernel.org, Frank.Li@nxp.com, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, gregkh@linuxfoundation.org, rafael@kernel.org, hanguidong02@gmail.com Cc: driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Danilo Krummrich , Alexander Stein Subject: [PATCH v2] clk: scu/imx8qxp: do not register driver in probe() Date: Fri, 13 Feb 2026 00:58:11 +0100 Message-ID: <20260212235842.85934-1-dakr@kernel.org> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" imx_clk_scu_init() registers the imx_clk_scu_driver while commonly being called from IMX driver's probe() callbacks. However, it neither makes sense to register drivers from probe() callbacks of other drivers, nor does the driver core allow registering drivers with a device lock already being held. The latter was revealed by commit dc23806a7c47 ("driver core: enforce device_lock for driver_match_device()") leading to a deadlock condition described in [1]. Besides that, nothing seems to unregister the imx_clk_scu_driver once the corresponding driver module is unloaded, which leaves the driver-core with a dangling pointer. Also, if there are multiple matching devices for the imx8qxp_clk_driver, imx8qxp_clk_probe() calls imx_clk_scu_init() multiple times. However, any subsequent call after the first one will fail, since the driver-core does not allow to register the same struct platform_driver multiple times. Hence, register the imx_clk_scu_driver from module_init() and unregister it in module_exit(). Note that we first register the imx8qxp_clk_driver and then call imx_clk_scu_module_init() to avoid having to call imx_clk_scu_module_exit() in the unwind path of imx8qxp_clk_init(). Fixes: dc23806a7c47 ("driver core: enforce device_lock for driver_match_dev= ice()") Fixes: 220175cd3979 ("clk: imx: scu: fix build break when compiled as modul= es") Reported-by: Alexander Stein Closes: https://lore.kernel.org/lkml/13955113.uLZWGnKmhe@steina-w/ Tested-by: Alexander Stein # TQMa8x/MBa8x Link: https://lore.kernel.org/lkml/DFU7CEPUSG9A.1KKGVW4HIPMSH@kernel.org/ [= 1] Signed-off-by: Danilo Krummrich Acked-by: Abel Vesa Reviewed-by: Daniel Baluta --- Changes in v2: - Expand commit message, mentioning a third bug fixed by this patch and n= oting the order of platform_driver_register() and imx_clk_scu_module_init() in imx8qxp_clk_init(). - Rename imx8qxp_{init,exit} to imx8qxp_clk_{init,exit}. - Link to v1: https://lore.kernel.org/driver-core/20260211142321.55404-1-= dakr@kernel.org/ --- drivers/clk/imx/clk-imx8qxp.c | 24 +++++++++++++++++++++++- drivers/clk/imx/clk-scu.c | 12 +++++++++++- drivers/clk/imx/clk-scu.h | 2 ++ 3 files changed, 36 insertions(+), 2 deletions(-) diff --git a/drivers/clk/imx/clk-imx8qxp.c b/drivers/clk/imx/clk-imx8qxp.c index 3ae162625bb1..c781425a005e 100644 --- a/drivers/clk/imx/clk-imx8qxp.c +++ b/drivers/clk/imx/clk-imx8qxp.c @@ -346,7 +346,29 @@ static struct platform_driver imx8qxp_clk_driver =3D { }, .probe =3D imx8qxp_clk_probe, }; -module_platform_driver(imx8qxp_clk_driver); + +static int __init imx8qxp_clk_init(void) +{ + int ret; + + ret =3D platform_driver_register(&imx8qxp_clk_driver); + if (ret) + return ret; + + ret =3D imx_clk_scu_module_init(); + if (ret) + platform_driver_unregister(&imx8qxp_clk_driver); + + return ret; +} +module_init(imx8qxp_clk_init); + +static void __exit imx8qxp_clk_exit(void) +{ + imx_clk_scu_module_exit(); + platform_driver_unregister(&imx8qxp_clk_driver); +} +module_exit(imx8qxp_clk_exit); =20 MODULE_AUTHOR("Aisheng Dong "); MODULE_DESCRIPTION("NXP i.MX8QXP clock driver"); diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c index 34c9dc1fb20e..c90d21e05f91 100644 --- a/drivers/clk/imx/clk-scu.c +++ b/drivers/clk/imx/clk-scu.c @@ -191,6 +191,16 @@ static bool imx_scu_clk_is_valid(u32 rsrc_id) return p !=3D NULL; } =20 +int __init imx_clk_scu_module_init(void) +{ + return platform_driver_register(&imx_clk_scu_driver); +} + +void __exit imx_clk_scu_module_exit(void) +{ + return platform_driver_unregister(&imx_clk_scu_driver); +} + int imx_clk_scu_init(struct device_node *np, const struct imx_clk_scu_rsrc_table *data) { @@ -215,7 +225,7 @@ int imx_clk_scu_init(struct device_node *np, rsrc_table =3D data; } =20 - return platform_driver_register(&imx_clk_scu_driver); + return 0; } =20 /* diff --git a/drivers/clk/imx/clk-scu.h b/drivers/clk/imx/clk-scu.h index af7b697f51ca..ca82f2cce897 100644 --- a/drivers/clk/imx/clk-scu.h +++ b/drivers/clk/imx/clk-scu.h @@ -25,6 +25,8 @@ extern const struct imx_clk_scu_rsrc_table imx_clk_scu_rs= rc_imx8dxl; extern const struct imx_clk_scu_rsrc_table imx_clk_scu_rsrc_imx8qxp; extern const struct imx_clk_scu_rsrc_table imx_clk_scu_rsrc_imx8qm; =20 +int __init imx_clk_scu_module_init(void); +void __exit imx_clk_scu_module_exit(void); int imx_clk_scu_init(struct device_node *np, const struct imx_clk_scu_rsrc_table *data); struct clk_hw *imx_scu_of_clk_src_get(struct of_phandle_args *clkspec, base-commit: 192c0159402e6bfbe13de6f8379546943297783d --=20 2.53.0