[PATCH net 2/2] Revert "net: fec: Use a spinlock to guard `fep->ptp_clk_on`"

From: Francesco Dolcini
Date: Mon Sep 12 2022 - 03:02:04 EST


This reverts commit b353b241f1eb9b6265358ffbe2632fdcb563354f, this is
creating multiple issues, just not ready to be merged yet.

Link: https://lore.kernel.org/all/CAHk-=wj1obPoTu1AHj9Bd_BGYjdjDyPP+vT5WMj8eheb3A9WHw@xxxxxxxxxxxxxx/
Link: https://lore.kernel.org/all/20220907143915.5w65kainpykfobte@xxxxxxxxxxxxxx/
Fixes: b353b241f1eb ("net: fec: Use a spinlock to guard `fep->ptp_clk_on`")
Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
---
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, 27 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index dcfe63f9be06..a5fed00cb971 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -561,6 +561,7 @@ struct fec_enet_private {
struct clk *clk_2x_txclk;

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 4ccd74af09ae..92c55e1a5507 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1995,7 +1995,6 @@ 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) {
@@ -2004,15 +2003,15 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
return ret;

if (fep->clk_ptp) {
- spin_lock_irqsave(&fep->tmreg_lock, flags);
+ mutex_lock(&fep->ptp_clk_mutex);
ret = clk_prepare_enable(fep->clk_ptp);
if (ret) {
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);
goto failed_clk_ptp;
} else {
fep->ptp_clk_on = true;
}
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);
}

ret = clk_prepare_enable(fep->clk_ref);
@@ -2027,10 +2026,10 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
} else {
clk_disable_unprepare(fep->clk_enet_out);
if (fep->clk_ptp) {
- spin_lock_irqsave(&fep->tmreg_lock, flags);
+ mutex_lock(&fep->ptp_clk_mutex);
clk_disable_unprepare(fep->clk_ptp);
fep->ptp_clk_on = false;
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);
}
clk_disable_unprepare(fep->clk_ref);
clk_disable_unprepare(fep->clk_2x_txclk);
@@ -2043,10 +2042,10 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
clk_disable_unprepare(fep->clk_ref);
failed_clk_ref:
if (fep->clk_ptp) {
- spin_lock_irqsave(&fep->tmreg_lock, flags);
+ mutex_lock(&fep->ptp_clk_mutex);
clk_disable_unprepare(fep->clk_ptp);
fep->ptp_clk_on = false;
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);
}
failed_clk_ptp:
clk_disable_unprepare(fep->clk_enet_out);
@@ -3881,7 +3880,7 @@ fec_probe(struct platform_device *pdev)
}

fep->ptp_clk_on = false;
- spin_lock_init(&fep->tmreg_lock);
+ mutex_init(&fep->ptp_clk_mutex);

/* clk_ref is optional, depends on board */
fep->clk_ref = devm_clk_get_optional(&pdev->dev, "enet_clk_ref");
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index af20aa237964..3dc3c0b626c2 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -365,19 +365,21 @@ 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 *fep =
+ struct fec_enet_private *adapter =
container_of(ptp, struct fec_enet_private, ptp_caps);
u64 ns;
unsigned long flags;

- spin_lock_irqsave(&fep->tmreg_lock, flags);
+ mutex_lock(&adapter->ptp_clk_mutex);
/* Check the ptp clock */
- if (!fep->ptp_clk_on) {
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ if (!adapter->ptp_clk_on) {
+ mutex_unlock(&adapter->ptp_clk_mutex);
return -EINVAL;
}
- ns = timecounter_read(&fep->tc);
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ 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);

*ts = ns_to_timespec64(ns);

@@ -402,10 +404,10 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp,
unsigned long flags;
u32 counter;

- spin_lock_irqsave(&fep->tmreg_lock, flags);
+ mutex_lock(&fep->ptp_clk_mutex);
/* Check the ptp clock */
if (!fep->ptp_clk_on) {
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);
return -EINVAL;
}

@@ -415,9 +417,11 @@ 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;
}

@@ -514,11 +518,13 @@ 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;

- spin_lock_irqsave(&fep->tmreg_lock, flags);
+ mutex_lock(&fep->ptp_clk_mutex);
if (fep->ptp_clk_on) {
+ spin_lock_irqsave(&fep->tmreg_lock, flags);
timecounter_read(&fep->tc);
+ spin_unlock_irqrestore(&fep->tmreg_lock, flags);
}
- spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+ mutex_unlock(&fep->ptp_clk_mutex);

schedule_delayed_work(&fep->time_keep, HZ);
}
@@ -593,6 +599,8 @@ 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);
--
2.25.1