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* [PATCH v2 0/1] net: fec: ptp: avoid register access when ipg clock is disabled
@ 2014-08-13  4:55 Fugang Duan
  2014-08-13  4:55 ` [PATCH v2 1/1] " Fugang Duan
  0 siblings, 1 reply; 19+ messages in thread
From: Fugang Duan @ 2014-08-13  4:55 UTC (permalink / raw)
  To: shawn.guo, davem, richardcochran; +Cc: netdev, b38611

V2:
* As Richard Cochran's suggestion, use schedule_delayed_work instead of period timer.
* Stop delayed work before ipg clock disable like suspend, ethx close.

Fugang Duan (1):
  net: fec: ptp: avoid register access when ipg clock is disabled

 drivers/net/ethernet/freescale/fec.h      |    2 +-
 drivers/net/ethernet/freescale/fec_main.c |   12 +++++++++++-
 drivers/net/ethernet/freescale/fec_ptp.c  |   15 +++++++--------
 3 files changed, 19 insertions(+), 10 deletions(-)

-- 
1.7.8

^ permalink raw reply	[flat|nested] 19+ messages in thread
* [PATCH v2 1/1] net: fec: ptp: avoid register access when ipg clock is disabled
@ 2021-02-25 20:55 Heiko Thiery
  2021-02-25 22:34   ` kernel test robot
  0 siblings, 1 reply; 19+ messages in thread
From: Heiko Thiery @ 2021-02-25 20:55 UTC (permalink / raw)
  To: netdev, linux-kernel
  Cc: Fugang Duan, David S . Miller, Jakub Kicinski, Richard Cochran,
	Heiko Thiery

When accessing the timecounter register on an i.MX8MQ the kernel hangs.
This is only the case when the interface is down. This can be reproduced
by reading with 'phc_ctrl eth0 get'.

Like described in the change in 91c0d987a9788dcc5fe26baafd73bf9242b68900
the igp clock is disabled when the interface is down and leads to a
system hang.

So we check if the ptp clock status before reading the timecounter
register.

Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
---
v2:
 - add mutex (thanks to Richard)

 drivers/net/ethernet/freescale/fec_ptp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index 2e344aada4c6..22f5e800c2d7 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -377,9 +377,15 @@ static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
 	u64 ns;
 	unsigned long flags;
 
+	mutex_lock(&fep->ptp_clk_mutex);
+	/* Check the ptp clock */
+	if (!adapter->ptp_clk_on)
+		mutex_unlock(&fep->ptp_clk_mutex);
+		return -EINVAL;
 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
 	ns = timecounter_read(&adapter->tc);
 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+	mutex_unlock(&fep->ptp_clk_mutex);
 
 	*ts = ns_to_timespec64(ns);
 
-- 
2.30.0


^ permalink raw reply related	[flat|nested] 19+ messages in thread
* [PATCH v2 1/1] net: fec: ptp: avoid register access when ipg clock is disabled
@ 2021-02-25 21:15 Heiko Thiery
  2021-02-26  7:22 ` Heiko Thiery
  2021-02-26 15:23 ` Richard Cochran
  0 siblings, 2 replies; 19+ messages in thread
From: Heiko Thiery @ 2021-02-25 21:15 UTC (permalink / raw)
  To: netdev, linux-kernel
  Cc: Fugang Duan, David S . Miller, Jakub Kicinski, Richard Cochran,
	Heiko Thiery

When accessing the timecounter register on an i.MX8MQ the kernel hangs.
This is only the case when the interface is down. This can be reproduced
by reading with 'phc_ctrl eth0 get'.

Like described in the change in 91c0d987a9788dcc5fe26baafd73bf9242b68900
the igp clock is disabled when the interface is down and leads to a
system hang.

So we check if the ptp clock status before reading the timecounter
register.

Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
---
v2:
 - add mutex (thanks to Richard)

v3:
I did a mistake and did not test properly
 - add parenteses
 - fix the used variable

 drivers/net/ethernet/freescale/fec_ptp.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index 2e344aada4c6..1753807cbf97 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -377,9 +377,16 @@ static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
 	u64 ns;
 	unsigned long flags;
 
+	mutex_lock(&adapter->ptp_clk_mutex);
+	/* Check the ptp clock */
+	if (!adapter->ptp_clk_on) {
+		mutex_unlock(&adapter->ptp_clk_mutex);
+		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);
 
 	*ts = ns_to_timespec64(ns);
 
-- 
2.30.0


^ permalink raw reply related	[flat|nested] 19+ messages in thread
end of thread, other threads:[~2021-02-26 23:46 UTC | newest]

Thread overview: 19+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-08-13  4:55 [PATCH v2 0/1] net: fec: ptp: avoid register access when ipg clock is disabled Fugang Duan
2014-08-13  4:55 ` [PATCH v2 1/1] " Fugang Duan
2014-08-13 21:19   ` Richard Cochran
2014-08-14  1:28     ` fugang.duan
2014-08-14  8:10       ` Richard Cochran
2014-08-14  8:24         ` fugang.duan
2014-08-14  8:42           ` Richard Cochran
2014-08-14  9:02             ` fugang.duan
2014-08-14  9:12               ` Richard Cochran
2014-08-14  9:26                 ` fugang.duan
2014-08-14 14:33                   ` Richard Cochran
2014-08-15  3:23                     ` fugang.duan
2021-02-25 20:55 Heiko Thiery
2021-02-25 22:34 ` kernel test robot
2021-02-25 22:34   ` kernel test robot
2021-02-25 21:15 Heiko Thiery
2021-02-26  7:22 ` Heiko Thiery
2021-02-26 15:23 ` Richard Cochran
2021-02-26 23:44   ` Jakub Kicinski

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