[tip: timers/ptp] igc: Use provided clock ID for history snapshot

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the timers/ptp branch of tip:

Commit-ID:     af1816babcd9eff5c40eaf0de149b469debdfdb4
Gitweb:        https://git.kernel.org/tip/af1816babcd9eff5c40eaf0de149b469debdfdb4
Author:        Thomas Gleixner <tglx@xxxxxxxxxx>
AuthorDate:    Fri, 29 May 2026 22:00:44 +02:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
CommitterDate: Thu, 04 Jun 2026 11:04:17 +02:00

igc: Use provided clock ID for history snapshot

The PTP core indicates in system_device_crosststamp::clock_id the clock ID
for which the system time stamp should be taken. That allows to utilize
hardware timestamps with e.g. AUX clocks.

Save the provided clock ID and use it in igc_phc_get_syncdevicetime() for
taking the history snapshot.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Tested-by: Arthur Kiyanovski <akiyano@xxxxxxxxxx>
Reviewed-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Link: https://patch.msgid.link/20260529195557.637381831@xxxxxxxxxx
---
 drivers/net/ethernet/intel/igc/igc.h     | 1 +
 drivers/net/ethernet/intel/igc/igc_ptp.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 1723681..46d625b 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -326,6 +326,7 @@ struct igc_adapter {
 	struct timespec64 prev_ptp_time; /* Pre-reset PTP clock */
 	ktime_t ptp_reset_start; /* Reset time in clock mono */
 	struct system_time_snapshot snapshot;
+	clockid_t snapshot_clock_id;
 	struct mutex ptm_lock; /* Only allow one PTM transaction at a time */
 
 	char fw_version[32];
diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index 3d6b226..b40aba9 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -1049,7 +1049,7 @@ static int igc_phc_get_syncdevicetime(ktime_t *device,
 	 */
 	do {
 		/* Get a snapshot of system clocks to use as historic value. */
-		ktime_get_snapshot(&adapter->snapshot);
+		ktime_get_snapshot_id(adapter->snapshot_clock_id, &adapter->snapshot);
 
 		igc_ptm_trigger(hw);
 
@@ -1103,6 +1103,8 @@ static int igc_ptp_getcrosststamp(struct ptp_clock_info *ptp,
 	/* This blocks until any in progress PTM transactions complete */
 	mutex_lock(&adapter->ptm_lock);
 
+	adapter->snapshot_clock_id = cts->clock_id;
+
 	ret = get_device_system_crosststamp(igc_phc_get_syncdevicetime,
 					    adapter, &adapter->snapshot, cts);
 	mutex_unlock(&adapter->ptm_lock);