From: Csókás Bence csokas.bence@prolan.hu
[ 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 is disabled") Fixes: f79959220fa5 ("fec: Restart PPS after link state change") Reported-by: Marc Kleine-Budde mkl@pengutronix.de Link: https://lore.kernel.org/all/20220827160922.642zlcd5foopozru@pengutronix.de/ Signed-off-by: Csókás Bence csokas.bence@prolan.hu Tested-by: Francesco Dolcini francesco.dolcini@toradex.com # Toradex Apalis iMX6 Link: https://lore.kernel.org/r/20220901140402.64804-1-csokas.bence@prolan.hu Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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/freescale/fec.h index 6ea98af63b341..e7b23d4a22d0a 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -523,7 +523,6 @@ struct fec_enet_private { struct clk *clk_ptp;
bool ptp_clk_on; - struct mutex ptp_clk_mutex; unsigned int num_tx_queues; unsigned int num_rx_queues;
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index d8bdaf2e5365c..674591751a676 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1937,6 +1937,7 @@ 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) { @@ -1945,15 +1946,15 @@ 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); @@ -1964,10 +1965,10 @@ 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); } @@ -1976,10 +1977,10 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
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); @@ -3665,7 +3666,7 @@ fec_probe(struct platform_device *pdev) fep->clk_enet_out = NULL;
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(&pdev->dev, "enet_clk_ref"); diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/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 = + struct fec_enet_private *fep = container_of(ptp, struct fec_enet_private, ptp_caps); u64 ns; unsigned long flags;
- 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 = timecounter_read(&adapter->tc); - spin_unlock_irqrestore(&adapter->tmreg_lock, flags); - mutex_unlock(&adapter->ptp_clk_mutex); + ns = timecounter_read(&fep->tc); + spin_unlock_irqrestore(&fep->tmreg_lock, flags);
*ts = ns_to_timespec64(ns);
@@ -405,10 +403,10 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp, unsigned long flags; u32 counter;
- 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; }
@@ -418,11 +416,9 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp, */ counter = ns & fep->cc.mask;
- 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; }
@@ -523,13 +519,11 @@ static void fec_time_keep(struct work_struct *work) struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep); unsigned long flags;
- 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);
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 = NSEC_PER_SEC / fep->cycle_speed;
- spin_lock_init(&fep->tmreg_lock); - fec_ptp_start_cyclecounter(ndev);
INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);