[PATCH] ptp: ocp: Fix PCI delay estimation

[PATCH] ptp: ocp: Fix PCI delay estimation

[Antoine Gagniere]

Since linux 6.12, a sign error causes the initial value of ts_window_adjust, (used in gettimex64) to be impossibly high, causing consumers like chrony to reject readings from PTP_SYS_OFFSET_EXTENDED.

This patch fixes ts_window_adjust's inital value and the sign-ness of various format flags

Context
-------

The value stored in the read-write attribute ts_window_adjust is a number of nanoseconds subtracted to the post_ts timestamp of the reading in gettimex64, used notably in the ioctl PTP_SYS_OFFSET_EXTENDED, to compensate for PCI delay.
Its initial value is set by estimating PCI delay.

Bug
---

The PCI delay estimation starts with the value U64_MAX and makes 3 measurements, taking the minimum value.
However because the delay was stored in a s64, U64_MAX was interpreted as -1, which compared as smaller than any positive values measured.
Then, that delay is divided by ~10 and placed in ts_window_adjust, which is a u32.
So ts_window_adjust ends up with (u32)(((s64)U64_MAX >> 5) * 3) inside, which is 4294967293

Symptom
-------

The consequence was that the post_ts of gettimex64, returned by PTP_SYS_OFFSET_EXTENDED, was substracted 4.29 seconds.
As a consequence chrony rejected all readings from the PHC

Difficulty to diagnose
----------------------

Using cat to read the attribute value showed -3 because the format flags %d was used instead of %u, resulting in a re-interpret cast.

Fixes
-----

1. Using U32_MAX as initial value for PCI delays: no one is expecting an ioread to take more than 4 s
   This will correctly compare as bigger that actual PCI delay measurements.
2. Fixing the sign of various format flags

Signed-off-by: Antoine Gagniere <antoine@gagniere.dev>
---
 drivers/ptp/ptp_ocp.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index b651087f426f..153827722a63 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -1558,7 +1558,8 @@ ptp_ocp_watchdog(struct timer_list *t)
 static void
 ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
 {
-	ktime_t start, end, delay = U64_MAX;
+	ktime_t start, end;
+	s64 delay_ns = U32_MAX; /* 4.29 seconds is high enough */
 	u32 ctrl;
 	int i;
 
@@ -1568,15 +1569,16 @@ ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
 
 		iowrite32(ctrl, &bp->reg->ctrl);
 
-		start = ktime_get_raw_ns();
+		start = ktime_get_raw();
 
 		ctrl = ioread32(&bp->reg->ctrl);
 
-		end = ktime_get_raw_ns();
+		end = ktime_get_raw();
 
-		delay = min(delay, end - start);
+		delay_ns = min(delay_ns, ktime_to_ns(end - start));
 	}
-	bp->ts_window_adjust = (delay >> 5) * 3;
+	delay_ns = max(0, delay_ns);
+	bp->ts_window_adjust = (delay_ns >> 5) * 3;
 }
 
 static int
@@ -1894,7 +1896,7 @@ ptp_ocp_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
 	int err;
 
 	fw_image = bp->fw_loader ? "loader" : "fw";
-	sprintf(buf, "%d.%d", bp->fw_tag, bp->fw_version);
+	sprintf(buf, "%hhu.%hu", bp->fw_tag, bp->fw_version);
 	err = devlink_info_version_running_put(req, fw_image, buf);
 	if (err)
 		return err;
@@ -3196,7 +3198,7 @@ signal_show(struct device *dev, struct device_attribute *attr, char *buf)
 	i = (uintptr_t)ea->var;
 	signal = &bp->signal[i];
 
-	count = sysfs_emit(buf, "%llu %d %llu %d", signal->period,
+	count = sysfs_emit(buf, "%lli %d %lli %d", signal->period,
 			   signal->duty, signal->phase, signal->polarity);
 
 	ts = ktime_to_timespec64(signal->start);
@@ -3230,7 +3232,7 @@ period_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct ptp_ocp *bp = dev_get_drvdata(dev);
 	int i = (uintptr_t)ea->var;
 
-	return sysfs_emit(buf, "%llu\n", bp->signal[i].period);
+	return sysfs_emit(buf, "%lli\n", bp->signal[i].period);
 }
 static EXT_ATTR_RO(signal, period, 0);
 static EXT_ATTR_RO(signal, period, 1);
@@ -3244,7 +3246,7 @@ phase_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct ptp_ocp *bp = dev_get_drvdata(dev);
 	int i = (uintptr_t)ea->var;
 
-	return sysfs_emit(buf, "%llu\n", bp->signal[i].phase);
+	return sysfs_emit(buf, "%lli\n", bp->signal[i].phase);
 }
 static EXT_ATTR_RO(signal, phase, 0);
 static EXT_ATTR_RO(signal, phase, 1);
@@ -3289,7 +3291,7 @@ start_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct timespec64 ts;
 
 	ts = ktime_to_timespec64(bp->signal[i].start);
-	return sysfs_emit(buf, "%llu.%lu\n", ts.tv_sec, ts.tv_nsec);
+	return sysfs_emit(buf, "%lli.%li\n", ts.tv_sec, ts.tv_nsec);
 }
 static EXT_ATTR_RO(signal, start, 0);
 static EXT_ATTR_RO(signal, start, 1);
@@ -3444,7 +3446,7 @@ utc_tai_offset_show(struct device *dev,
 {
 	struct ptp_ocp *bp = dev_get_drvdata(dev);
 
-	return sysfs_emit(buf, "%d\n", bp->utc_tai_offset);
+	return sysfs_emit(buf, "%u\n", bp->utc_tai_offset);
 }
 
 static ssize_t
@@ -3472,7 +3474,7 @@ ts_window_adjust_show(struct device *dev,
 {
 	struct ptp_ocp *bp = dev_get_drvdata(dev);
 
-	return sysfs_emit(buf, "%d\n", bp->ts_window_adjust);
+	return sysfs_emit(buf, "%u\n", bp->ts_window_adjust);
 }
 
 static ssize_t
@@ -3964,7 +3966,7 @@ _signal_summary_show(struct seq_file *s, struct ptp_ocp *bp, int nr)
 
 	on = signal->running;
 	sprintf(label, "GEN%d", nr + 1);
-	seq_printf(s, "%7s: %s, period:%llu duty:%d%% phase:%llu pol:%d",
+	seq_printf(s, "%7s: %s, period:%lli duty:%d%% phase:%lli pol:%d",
 		   label, on ? " ON" : "OFF",
 		   signal->period, signal->duty, signal->phase,
 		   signal->polarity);
@@ -3974,7 +3976,7 @@ _signal_summary_show(struct seq_file *s, struct ptp_ocp *bp, int nr)
 	val = ioread32(&reg->status);
 	seq_printf(s, " %x]", val);
 
-	seq_printf(s, " start:%llu\n", signal->start);
+	seq_printf(s, " start:%lli\n", signal->start);
 }
 
 static void
@@ -4231,7 +4233,7 @@ ptp_ocp_summary_show(struct seq_file *s, void *data)
 
 		seq_printf(s, "%7s: %lld.%ld == %ptT TAI\n", "PHC",
 			   ts.tv_sec, ts.tv_nsec, &ts);
-		seq_printf(s, "%7s: %lld.%ld == %ptT UTC offset %d\n", "SYS",
+		seq_printf(s, "%7s: %lld.%ld == %ptT UTC offset %u\n", "SYS",
 			   sys_ts.tv_sec, sys_ts.tv_nsec, &sys_ts,
 			   bp->utc_tai_offset);
 		seq_printf(s, "%7s: PHC:SYS offset: %lld  window: %lld\n", "",
-- 
2.48.1

Re: [PATCH] ptp: ocp: Fix PCI delay estimation

[Vadim Fedorenko]

On 17/08/2025 23:29, Antoine Gagniere wrote:
> Since linux 6.12, a sign error causes the initial value of ts_window_adjust, (used in gettimex64) to be impossibly high, causing consumers like chrony to reject readings from PTP_SYS_OFFSET_EXTENDED.
> 
> This patch fixes ts_window_adjust's inital value and the sign-ness of various format flags
> 
> Context
> -------
> 
> The value stored in the read-write attribute ts_window_adjust is a number of nanoseconds subtracted to the post_ts timestamp of the reading in gettimex64, used notably in the ioctl PTP_SYS_OFFSET_EXTENDED, to compensate for PCI delay.
> Its initial value is set by estimating PCI delay.
> 
> Bug
> ---
> 
> The PCI delay estimation starts with the value U64_MAX and makes 3 measurements, taking the minimum value.
> However because the delay was stored in a s64, U64_MAX was interpreted as -1, which compared as smaller than any positive values measured.
> Then, that delay is divided by ~10 and placed in ts_window_adjust, which is a u32.
> So ts_window_adjust ends up with (u32)(((s64)U64_MAX >> 5) * 3) inside, which is 4294967293
> 
> Symptom
> -------
> 
> The consequence was that the post_ts of gettimex64, returned by PTP_SYS_OFFSET_EXTENDED, was substracted 4.29 seconds.
> As a consequence chrony rejected all readings from the PHC
> 
> Difficulty to diagnose
> ----------------------
> 
> Using cat to read the attribute value showed -3 because the format flags %d was used instead of %u, resulting in a re-interpret cast.
> 
> Fixes
> -----
> 
> 1. Using U32_MAX as initial value for PCI delays: no one is expecting an ioread to take more than 4 s
>     This will correctly compare as bigger that actual PCI delay measurements.
> 2. Fixing the sign of various format flags
> 
> Signed-off-by: Antoine Gagniere <antoine@gagniere.dev>
> ---
>   drivers/ptp/ptp_ocp.c | 32 +++++++++++++++++---------------
>   1 file changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
> index b651087f426f..153827722a63 100644
> --- a/drivers/ptp/ptp_ocp.c
> +++ b/drivers/ptp/ptp_ocp.c
> @@ -1558,7 +1558,8 @@ ptp_ocp_watchdog(struct timer_list *t)
>   static void
>   ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
>   {
> -	ktime_t start, end, delay = U64_MAX;
> +	ktime_t start, end;
> +	s64 delay_ns = U32_MAX; /* 4.29 seconds is high enough */
>   	u32 ctrl;
>   	int i;
>   
> @@ -1568,15 +1569,16 @@ ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
>   
>   		iowrite32(ctrl, &bp->reg->ctrl);
>   
> -		start = ktime_get_raw_ns();
> +		start = ktime_get_raw();
>   
>   		ctrl = ioread32(&bp->reg->ctrl);
>   
> -		end = ktime_get_raw_ns();
> +		end = ktime_get_raw();
>   
> -		delay = min(delay, end - start);
> +		delay_ns = min(delay_ns, ktime_to_ns(end - start));
>   	}
> -	bp->ts_window_adjust = (delay >> 5) * 3;
> +	delay_ns = max(0, delay_ns);

I don't believe we can get a negative value from
ktime_to_ns(end - start), and that means that delay_ns will always be
positive and there is no need for the last max().

Apart from that the patch LGTM,
Thanks

> +	bp->ts_window_adjust = (delay_ns >> 5) * 3;
>   }
>   

Re: [PATCH] ptp: ocp: Fix PCI delay estimation

[Vadim Fedorenko]

On 17/08/2025 23:29, Antoine Gagniere wrote:
> Since linux 6.12, a sign error causes the initial value of ts_window_adjust, (used in gettimex64) to be impossibly high, causing consumers like chrony to reject readings from PTP_SYS_OFFSET_EXTENDED.
> 
> This patch fixes ts_window_adjust's inital value and the sign-ness of various format flags
> 
> Context
> -------
> 
> The value stored in the read-write attribute ts_window_adjust is a number of nanoseconds subtracted to the post_ts timestamp of the reading in gettimex64, used notably in the ioctl PTP_SYS_OFFSET_EXTENDED, to compensate for PCI delay.
> Its initial value is set by estimating PCI delay.
> 
> Bug
> ---
> 
> The PCI delay estimation starts with the value U64_MAX and makes 3 measurements, taking the minimum value.
> However because the delay was stored in a s64, U64_MAX was interpreted as -1, which compared as smaller than any positive values measured.
> Then, that delay is divided by ~10 and placed in ts_window_adjust, which is a u32.
> So ts_window_adjust ends up with (u32)(((s64)U64_MAX >> 5) * 3) inside, which is 4294967293
> 
> Symptom
> -------
> 
> The consequence was that the post_ts of gettimex64, returned by PTP_SYS_OFFSET_EXTENDED, was substracted 4.29 seconds.
> As a consequence chrony rejected all readings from the PHC
> 
> Difficulty to diagnose
> ----------------------
> 
> Using cat to read the attribute value showed -3 because the format flags %d was used instead of %u, resulting in a re-interpret cast.
> 
> Fixes
> -----
> 
> 1. Using U32_MAX as initial value for PCI delays: no one is expecting an ioread to take more than 4 s
>     This will correctly compare as bigger that actual PCI delay measurements.
> 2. Fixing the sign of various format flags
> 
> Signed-off-by: Antoine Gagniere <antoine@gagniere.dev>

JFYI, for the next version could you please organize the commit message
to fit into 80 chars per line and specify net tree as well as patch
which you believe introduced the problem using Fixes tag.

More details on formatting can be found at
https://docs.kernel.org/process/submitting-patches.html#submittingpatches

Re: [PATCH] ptp: ocp: Fix PCI delay estimation

[Antoine Gagniere]

>>   static void
>>   ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
>>   {
>> -	ktime_t start, end, delay = U64_MAX;
>> +	ktime_t start, end;
>> +	s64 delay_ns = U32_MAX; /* 4.29 seconds is high enough */
>>   	u32 ctrl;
>>   	int i;
>>
>> @@ -1568,15 +1569,16 @@ ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
>>
>>   		iowrite32(ctrl, &bp->reg->ctrl);
>>
>> -		start = ktime_get_raw_ns();
>> +		start = ktime_get_raw();
>>
>>   		ctrl = ioread32(&bp->reg->ctrl);
>>
>> -		end = ktime_get_raw_ns();
>> +		end = ktime_get_raw();
>>
>> -		delay = min(delay, end - start);
>> +		delay_ns = min(delay_ns, ktime_to_ns(end - start));
>>   	}
>> -	bp->ts_window_adjust = (delay >> 5) * 3;
>> +	delay_ns = max(0, delay_ns);0
>
> I don't believe we can get a negative value from
> ktime_to_ns(end - start), and that means that delay_ns will always be
> positive and there is no need for the last max().

You are correct, ktime is monotonic, this was an excess of zeal
on my part.


> JFYI, for the next version could you please organize the commit message
> to fit into 80 chars per line and specify net tree as well as patch
> which you believe introduced the problem using Fixes tag.
>
> More details on formatting can be found at
> https://docs.kernel.org/process/submitting-patches.html#submittingpatches

Thanks for the link, I was looking for such documentation but somehow missed this page

Will attempt a v2 later this week

Re: [PATCH] ptp: ocp: Fix PCI delay estimation

[David Laight]

On Mon, 18 Aug 2025 00:29:33 +0200
Antoine Gagniere <antoine@gagniere.dev> wrote:

> Since linux 6.12, a sign error causes the initial value of ts_window_adjust, (used in gettimex64) to be impossibly high, causing consumers like chrony to reject readings from PTP_SYS_OFFSET_EXTENDED.
> 
> This patch fixes ts_window_adjust's inital value and the sign-ness of various format flags
> 
> Context
> -------
> 
> The value stored in the read-write attribute ts_window_adjust is a number of nanoseconds subtracted to the post_ts timestamp of the reading in gettimex64, used notably in the ioctl PTP_SYS_OFFSET_EXTENDED, to compensate for PCI delay.
> Its initial value is set by estimating PCI delay.
> 
> Bug
> ---
> 
> The PCI delay estimation starts with the value U64_MAX and makes 3 measurements, taking the minimum value.
> However because the delay was stored in a s64, U64_MAX was interpreted as -1, which compared as smaller than any positive values measured.
> Then, that delay is divided by ~10 and placed in ts_window_adjust, which is a u32.
> So ts_window_adjust ends up with (u32)(((s64)U64_MAX >> 5) * 3) inside, which is 4294967293
> 
> Symptom
> -------
> 
> The consequence was that the post_ts of gettimex64, returned by PTP_SYS_OFFSET_EXTENDED, was substracted 4.29 seconds.
> As a consequence chrony rejected all readings from the PHC
> 
> Difficulty to diagnose
> ----------------------
> 
> Using cat to read the attribute value showed -3 because the format flags %d was used instead of %u, resulting in a re-interpret cast.
> 
> Fixes
> -----
> 
> 1. Using U32_MAX as initial value for PCI delays: no one is expecting an ioread to take more than 4 s
>    This will correctly compare as bigger that actual PCI delay measurements.
> 2. Fixing the sign of various format flags
> 
> Signed-off-by: Antoine Gagniere <antoine@gagniere.dev>
> ---
>  drivers/ptp/ptp_ocp.c | 32 +++++++++++++++++---------------
>  1 file changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
> index b651087f426f..153827722a63 100644
> --- a/drivers/ptp/ptp_ocp.c
> +++ b/drivers/ptp/ptp_ocp.c
> @@ -1558,7 +1558,8 @@ ptp_ocp_watchdog(struct timer_list *t)
>  static void
>  ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
>  {
> -	ktime_t start, end, delay = U64_MAX;
> +	ktime_t start, end;
> +	s64 delay_ns = U32_MAX; /* 4.29 seconds is high enough */

Isn't this the only change that matters?
Changing from ktime_get_raw_ns() to ktime_get_raw() is pointless.
Both are 64 bit and are not going to wrap.
(This is ignoring the fact that I think they are always identical.)

>  	u32 ctrl;
>  	int i;
>  
> @@ -1568,15 +1569,16 @@ ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
>  
>  		iowrite32(ctrl, &bp->reg->ctrl);
>  
> -		start = ktime_get_raw_ns();
> +		start = ktime_get_raw();
>  
>  		ctrl = ioread32(&bp->reg->ctrl);
>  
> -		end = ktime_get_raw_ns();
> +		end = ktime_get_raw();
>  
> -		delay = min(delay, end - start);
> +		delay_ns = min(delay_ns, ktime_to_ns(end - start));
>  	}
> -	bp->ts_window_adjust = (delay >> 5) * 3;
> +	delay_ns = max(0, delay_ns);
> +	bp->ts_window_adjust = (delay_ns >> 5) * 3;
>  }
>  
>  static int
> @@ -1894,7 +1896,7 @@ ptp_ocp_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
>  	int err;
>  
>  	fw_image = bp->fw_loader ? "loader" : "fw";
> -	sprintf(buf, "%d.%d", bp->fw_tag, bp->fw_version);
> +	sprintf(buf, "%hhu.%hu", bp->fw_tag, bp->fw_version);

WTF is %hhu about?
The varargs parameters are subject to integer promotion, %d or %u is fine.

>  	err = devlink_info_version_running_put(req, fw_image, buf);
>  	if (err)
>  		return err;
> @@ -3196,7 +3198,7 @@ signal_show(struct device *dev, struct device_attribute *attr, char *buf)
>  	i = (uintptr_t)ea->var;
>  	signal = &bp->signal[i];
>  
> -	count = sysfs_emit(buf, "%llu %d %llu %d", signal->period,
> +	count = sysfs_emit(buf, "%lli %d %lli %d", signal->period,

Use %lld not %lli (and below).

	David


>  			   signal->duty, signal->phase, signal->polarity);
>  
>  	ts = ktime_to_timespec64(signal->start);
> @@ -3230,7 +3232,7 @@ period_show(struct device *dev, struct device_attribute *attr, char *buf)
>  	struct ptp_ocp *bp = dev_get_drvdata(dev);
>  	int i = (uintptr_t)ea->var;
>  
> -	return sysfs_emit(buf, "%llu\n", bp->signal[i].period);
> +	return sysfs_emit(buf, "%lli\n", bp->signal[i].period);
>  }
>  static EXT_ATTR_RO(signal, period, 0);
>  static EXT_ATTR_RO(signal, period, 1);
> @@ -3244,7 +3246,7 @@ phase_show(struct device *dev, struct device_attribute *attr, char *buf)
>  	struct ptp_ocp *bp = dev_get_drvdata(dev);
>  	int i = (uintptr_t)ea->var;
>  
> -	return sysfs_emit(buf, "%llu\n", bp->signal[i].phase);
> +	return sysfs_emit(buf, "%lli\n", bp->signal[i].phase);
>  }
>  static EXT_ATTR_RO(signal, phase, 0);
>  static EXT_ATTR_RO(signal, phase, 1);
> @@ -3289,7 +3291,7 @@ start_show(struct device *dev, struct device_attribute *attr, char *buf)
>  	struct timespec64 ts;
>  
>  	ts = ktime_to_timespec64(bp->signal[i].start);
> -	return sysfs_emit(buf, "%llu.%lu\n", ts.tv_sec, ts.tv_nsec);
> +	return sysfs_emit(buf, "%lli.%li\n", ts.tv_sec, ts.tv_nsec);
>  }
>  static EXT_ATTR_RO(signal, start, 0);
>  static EXT_ATTR_RO(signal, start, 1);
> @@ -3444,7 +3446,7 @@ utc_tai_offset_show(struct device *dev,
>  {
>  	struct ptp_ocp *bp = dev_get_drvdata(dev);
>  
> -	return sysfs_emit(buf, "%d\n", bp->utc_tai_offset);
> +	return sysfs_emit(buf, "%u\n", bp->utc_tai_offset);
>  }
>  
>  static ssize_t
> @@ -3472,7 +3474,7 @@ ts_window_adjust_show(struct device *dev,
>  {
>  	struct ptp_ocp *bp = dev_get_drvdata(dev);
>  
> -	return sysfs_emit(buf, "%d\n", bp->ts_window_adjust);
> +	return sysfs_emit(buf, "%u\n", bp->ts_window_adjust);
>  }
>  
>  static ssize_t
> @@ -3964,7 +3966,7 @@ _signal_summary_show(struct seq_file *s, struct ptp_ocp *bp, int nr)
>  
>  	on = signal->running;
>  	sprintf(label, "GEN%d", nr + 1);
> -	seq_printf(s, "%7s: %s, period:%llu duty:%d%% phase:%llu pol:%d",
> +	seq_printf(s, "%7s: %s, period:%lli duty:%d%% phase:%lli pol:%d",
>  		   label, on ? " ON" : "OFF",
>  		   signal->period, signal->duty, signal->phase,
>  		   signal->polarity);
> @@ -3974,7 +3976,7 @@ _signal_summary_show(struct seq_file *s, struct ptp_ocp *bp, int nr)
>  	val = ioread32(&reg->status);
>  	seq_printf(s, " %x]", val);
>  
> -	seq_printf(s, " start:%llu\n", signal->start);
> +	seq_printf(s, " start:%lli\n", signal->start);
>  }
>  
>  static void
> @@ -4231,7 +4233,7 @@ ptp_ocp_summary_show(struct seq_file *s, void *data)
>  
>  		seq_printf(s, "%7s: %lld.%ld == %ptT TAI\n", "PHC",
>  			   ts.tv_sec, ts.tv_nsec, &ts);
> -		seq_printf(s, "%7s: %lld.%ld == %ptT UTC offset %d\n", "SYS",
> +		seq_printf(s, "%7s: %lld.%ld == %ptT UTC offset %u\n", "SYS",
>  			   sys_ts.tv_sec, sys_ts.tv_nsec, &sys_ts,
>  			   bp->utc_tai_offset);
>  		seq_printf(s, "%7s: PHC:SYS offset: %lld  window: %lld\n", "",