[PATCH net v1] iavf: add missing PTP adjustment callbacks

[Xuanqiang Luo <xuanqiang.luo@linux.dev>]

From: Xuanqiang Luo <luoxuanqiang@kylinos.cn>

The PTP hardware clock documentation requires drivers to implement all
callbacks and return -EOPNOTSUPP for unsupported features.

The iavf driver registers a PHC without adjtime or adjfine callbacks.
A userspace clock_adjtime(2) request reaches ptp_clock_adjtime(), where
ADJ_SETOFFSET calls adjtime and ADJ_FREQUENCY calls adjfine. The missing
callbacks can therefore cause a NULL dereference.

Provide both callbacks and return -EOPNOTSUPP for the unsupported
operations.

Fixes: d734223b2f0d ("iavf: add initial framework for registering PTP clock")
Link: https://docs.kernel.org/driver-api/ptp.html#writing-clock-drivers
Link: https://lore.kernel.org/all/20260826101004.100979-1-xuanqiang.luo@linux.dev/
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
---
 drivers/net/ethernet/intel/iavf/iavf_ptp.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_ptp.c b/drivers/net/ethernet/intel/iavf/iavf_ptp.c
index 87b97e09df14a..fcb273828bc1b 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_ptp.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_ptp.c
@@ -252,6 +252,16 @@ static int iavf_ptp_gettimex64(struct ptp_clock_info *info,
 	return iavf_read_phc_indirect(adapter, ts, sts);
 }
 
+static int iavf_ptp_adjfine(struct ptp_clock_info *info, long scaled_ppm)
+{
+	return -EOPNOTSUPP;
+}
+
+static int iavf_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
+{
+	return -EOPNOTSUPP;
+}
+
 static int iavf_ptp_settime64(struct ptp_clock_info *info,
 			      const struct timespec64 *ts)
 {
@@ -326,6 +336,8 @@ static int iavf_ptp_register_clock(struct iavf_adapter *adapter)
 		 KBUILD_MODNAME, dev_name(dev));
 	ptp_info->owner = THIS_MODULE;
 	ptp_info->gettimex64 = iavf_ptp_gettimex64;
+	ptp_info->adjfine = iavf_ptp_adjfine;
+	ptp_info->adjtime = iavf_ptp_adjtime;
 	ptp_info->settime64 = iavf_ptp_settime64;
 	ptp_info->do_aux_work = iavf_ptp_do_aux_work;
 
-- 
2.43.0