[patch 11/24] timekeeping: Add CLOCK ID to system_device_crosststamp
From: Thomas Gleixner
Date: Tue May 26 2026 - 13:46:54 EST
The normal capture for system/device cross timestamps is CLOCK_REALTIME,
but that's meaningless for AUX clocks.
Add a clock_id field to struct system_device_crosststamp and initialize it
with CLOCK_REALTIME at the two places which prepare for cross
timestamps.
After the related code has been cleaned up, the core code will honor the
clock_id field when calculating the system time from the system counter
snapshot.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
---
drivers/ptp/ptp_chardev.c | 2 +-
include/linux/timekeeping.h | 2 ++
sound/hda/common/controller.c | 2 +-
3 files changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -317,8 +317,8 @@ typedef int (*ptp_crosststamp_fn)(struct
static long ptp_sys_offset_precise(struct ptp_clock *ptp, void __user *arg,
ptp_crosststamp_fn crosststamp_fn)
{
+ struct system_device_crosststamp xtstamp = { .clock_id = CLOCK_REALTIME };
struct ptp_sys_offset_precise precise_offset;
- struct system_device_crosststamp xtstamp;
struct timespec64 ts;
int err;
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -315,12 +315,14 @@ struct system_counterval_t {
/**
* struct system_device_crosststamp - system/device cross-timestamp
* (synchronized capture)
+ * @clock_id: System time Clock ID to capture
* @device: Device time
* @sys_counter: Clocksource counter value simultaneous with device time
* @sys_realtime: Realtime simultaneous with device time
* @sys_monoraw: Monotonic raw simultaneous with device time
*/
struct system_device_crosststamp {
+ clockid_t clock_id;
ktime_t device;
struct system_counterval_t sys_counter;
ktime_t sys_realtime;
--- a/sound/hda/common/controller.c
+++ b/sound/hda/common/controller.c
@@ -489,9 +489,9 @@ static int azx_get_time_info(struct snd_
struct snd_pcm_audio_tstamp_config *audio_tstamp_config,
struct snd_pcm_audio_tstamp_report *audio_tstamp_report)
{
+ struct system_device_crosststamp xtstamp = { .clock_id = CLOCK_REALTIME };
struct azx_dev *azx_dev = get_azx_dev(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
- struct system_device_crosststamp xtstamp;
int ret;
u64 nsec;