From nobody Sun Sep 14 22:46:34 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6A73C54EE9 for ; Tue, 13 Sep 2022 14:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234379AbiIMOkB (ORCPT ); Tue, 13 Sep 2022 10:40:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234321AbiIMOhM (ORCPT ); Tue, 13 Sep 2022 10:37:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AC866B8E2; Tue, 13 Sep 2022 07:20:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9CADA614A8; Tue, 13 Sep 2022 14:19:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E429C433D6; Tue, 13 Sep 2022 14:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1663078794; bh=Q83UYvvGgPJ5Yy7LZn6xwgV627m5YsW0M8zEvrvHtNk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qxgj6+RCAkZGKyG56gB9DYnGiYRk1vO2rAUBRccOkYNhpiQWFl1uj4xYM8y3nqaII O/wcxteXm696qUEUm8M8RKU/tMzDQy32CGrke06cZbxGWvNvr0gGAVH5Gps0keg80x Uiqr++0PTmJLGtRAPYbA73plFYPblluDMHElbz8A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Kleine-Budde , =?UTF-8?q?Cs=C3=B3k=C3=A1s=20Bence?= , Jakub Kicinski , Sasha Levin , Francesco Dolcini Subject: [PATCH 5.15 084/121] net: fec: Use a spinlock to guard `fep->ptp_clk_on` Date: Tue, 13 Sep 2022 16:04:35 +0200 Message-Id: <20220913140400.979880696@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220913140357.323297659@linuxfoundation.org> References: <20220913140357.323297659@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Cs=C3=B3k=C3=A1s Bence [ Upstream commit b353b241f1eb9b6265358ffbe2632fdcb563354f ] Mutexes cannot be taken in a non-preemptible context, causing a panic in `fec_ptp_save_state()`. Replacing `ptp_clk_mutex` by `tmreg_lock` fixes this. Fixes: 6a4d7234ae9a ("net: fec: ptp: avoid register access when ipg clock i= s disabled") Fixes: f79959220fa5 ("fec: Restart PPS after link state change") Reported-by: Marc Kleine-Budde Link: https://lore.kernel.org/all/20220827160922.642zlcd5foopozru@pengutron= ix.de/ Signed-off-by: Cs=C3=B3k=C3=A1s Bence Tested-by: Francesco Dolcini # Toradex Apal= is iMX6 Link: https://lore.kernel.org/r/20220901140402.64804-1-csokas.bence@prolan.= hu Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/freescale/fec.h | 1 - drivers/net/ethernet/freescale/fec_main.c | 17 +++++++------- drivers/net/ethernet/freescale/fec_ptp.c | 28 ++++++++--------------- 3 files changed, 19 insertions(+), 27 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/fr= eescale/fec.h index ed7301b691694..939720a75f87c 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -557,7 +557,6 @@ struct fec_enet_private { struct clk *clk_2x_txclk; =20 bool ptp_clk_on; - struct mutex ptp_clk_mutex; unsigned int num_tx_queues; unsigned int num_rx_queues; =20 diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethern= et/freescale/fec_main.c index 67eb9b671244b..7561524e7c361 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1984,6 +1984,7 @@ static void fec_enet_phy_reset_after_clk_enable(struc= t net_device *ndev) static int fec_enet_clk_enable(struct net_device *ndev, bool enable) { struct fec_enet_private *fep =3D netdev_priv(ndev); + unsigned long flags; int ret; =20 if (enable) { @@ -1992,15 +1993,15 @@ static int fec_enet_clk_enable(struct net_device *n= dev, bool enable) return ret; =20 if (fep->clk_ptp) { - mutex_lock(&fep->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); ret =3D clk_prepare_enable(fep->clk_ptp); if (ret) { - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); goto failed_clk_ptp; } else { fep->ptp_clk_on =3D true; } - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); } =20 ret =3D clk_prepare_enable(fep->clk_ref); @@ -2015,10 +2016,10 @@ static int fec_enet_clk_enable(struct net_device *n= dev, bool enable) } else { clk_disable_unprepare(fep->clk_enet_out); if (fep->clk_ptp) { - mutex_lock(&fep->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); clk_disable_unprepare(fep->clk_ptp); fep->ptp_clk_on =3D false; - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); } clk_disable_unprepare(fep->clk_ref); clk_disable_unprepare(fep->clk_2x_txclk); @@ -2031,10 +2032,10 @@ static int fec_enet_clk_enable(struct net_device *n= dev, bool enable) clk_disable_unprepare(fep->clk_ref); failed_clk_ref: if (fep->clk_ptp) { - mutex_lock(&fep->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); clk_disable_unprepare(fep->clk_ptp); fep->ptp_clk_on =3D false; - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); } failed_clk_ptp: clk_disable_unprepare(fep->clk_enet_out); @@ -3866,7 +3867,7 @@ fec_probe(struct platform_device *pdev) fep->clk_enet_out =3D NULL; =20 fep->ptp_clk_on =3D false; - mutex_init(&fep->ptp_clk_mutex); + spin_lock_init(&fep->tmreg_lock); =20 /* clk_ref is optional, depends on board */ fep->clk_ref =3D devm_clk_get(&pdev->dev, "enet_clk_ref"); diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/etherne= t/freescale/fec_ptp.c index c5ae673005908..99bd67d3befd0 100644 --- a/drivers/net/ethernet/freescale/fec_ptp.c +++ b/drivers/net/ethernet/freescale/fec_ptp.c @@ -366,21 +366,19 @@ static int fec_ptp_adjtime(struct ptp_clock_info *ptp= , s64 delta) */ static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *= ts) { - struct fec_enet_private *adapter =3D + struct fec_enet_private *fep =3D container_of(ptp, struct fec_enet_private, ptp_caps); u64 ns; unsigned long flags; =20 - mutex_lock(&adapter->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); /* Check the ptp clock */ - if (!adapter->ptp_clk_on) { - mutex_unlock(&adapter->ptp_clk_mutex); + if (!fep->ptp_clk_on) { + spin_unlock_irqrestore(&fep->tmreg_lock, flags); return -EINVAL; } - spin_lock_irqsave(&adapter->tmreg_lock, flags); - ns =3D timecounter_read(&adapter->tc); - spin_unlock_irqrestore(&adapter->tmreg_lock, flags); - mutex_unlock(&adapter->ptp_clk_mutex); + ns =3D timecounter_read(&fep->tc); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); =20 *ts =3D ns_to_timespec64(ns); =20 @@ -405,10 +403,10 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp, unsigned long flags; u32 counter; =20 - mutex_lock(&fep->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); /* Check the ptp clock */ if (!fep->ptp_clk_on) { - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); return -EINVAL; } =20 @@ -418,11 +416,9 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp, */ counter =3D ns & fep->cc.mask; =20 - spin_lock_irqsave(&fep->tmreg_lock, flags); writel(counter, fep->hwp + FEC_ATIME); timecounter_init(&fep->tc, &fep->cc, ns); spin_unlock_irqrestore(&fep->tmreg_lock, flags); - mutex_unlock(&fep->ptp_clk_mutex); return 0; } =20 @@ -523,13 +519,11 @@ static void fec_time_keep(struct work_struct *work) struct fec_enet_private *fep =3D container_of(dwork, struct fec_enet_priv= ate, time_keep); unsigned long flags; =20 - mutex_lock(&fep->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); if (fep->ptp_clk_on) { - spin_lock_irqsave(&fep->tmreg_lock, flags); timecounter_read(&fep->tc); - spin_unlock_irqrestore(&fep->tmreg_lock, flags); } - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); =20 schedule_delayed_work(&fep->time_keep, HZ); } @@ -604,8 +598,6 @@ void fec_ptp_init(struct platform_device *pdev, int irq= _idx) } fep->ptp_inc =3D NSEC_PER_SEC / fep->cycle_speed; =20 - spin_lock_init(&fep->tmreg_lock); - fec_ptp_start_cyclecounter(ndev); =20 INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep); --=20 2.35.1