From b353b241f1eb9b6265358ffbe2632fdcb563354f Mon Sep 17 00:00:00 2001 From: Csókás Bence Date: Thu, 1 Sep 2022 16:04:03 +0200 Subject: net: fec: Use a spinlock to guard `fep->ptp_clk_on` MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 is disabled") Fixes: f79959220fa5 ("fec: Restart PPS after link state change") Reported-by: Marc Kleine-Budde Link: https://lore.kernel.org/all/20220827160922.642zlcd5foopozru@pengutronix.de/ Signed-off-by: Csókás Bence Tested-by: Francesco Dolcini # Toradex Apalis iMX6 Link: https://lore.kernel.org/r/20220901140402.64804-1-csokas.bence@prolan.hu Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/freescale/fec_main.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'drivers/net/ethernet/freescale/fec_main.c') diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 111aaef33080..6152f6dbf1bc 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -2029,6 +2029,7 @@ static void fec_enet_phy_reset_after_clk_enable(struct net_device *ndev) static int fec_enet_clk_enable(struct net_device *ndev, bool enable) { struct fec_enet_private *fep = netdev_priv(ndev); + unsigned long flags; int ret; if (enable) { @@ -2037,15 +2038,15 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) return ret; if (fep->clk_ptp) { - mutex_lock(&fep->ptp_clk_mutex); + spin_lock_irqsave(&fep->tmreg_lock, flags); ret = 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 = true; } - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); } ret = clk_prepare_enable(fep->clk_ref); @@ -2060,10 +2061,10 @@ static int fec_enet_clk_enable(struct net_device *ndev, 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 = 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); @@ -2076,10 +2077,10 @@ failed_clk_2x_txclk: 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 = false; - mutex_unlock(&fep->ptp_clk_mutex); + spin_unlock_irqrestore(&fep->tmreg_lock, flags); } failed_clk_ptp: clk_disable_unprepare(fep->clk_enet_out); @@ -3914,7 +3915,7 @@ fec_probe(struct platform_device *pdev) } fep->ptp_clk_on = false; - mutex_init(&fep->ptp_clk_mutex); + spin_lock_init(&fep->tmreg_lock); /* clk_ref is optional, depends on board */ fep->clk_ref = devm_clk_get_optional(&pdev->dev, "enet_clk_ref"); -- cgit v1.2.3-59-g8ed1b