[PATCH net] igb: initialize PTP lock before registering PHC

[Runyu Xiao]

igb_ptp_init() registers the PHC before initializing
adapter->tmreg_lock.  ptp_clock_register() publishes the PHC device,
so a userspace PTP operation can enter a callback and take the lock
before it has been initialized.

Initialize tmreg_lock before registering the PHC so all published PTP
callbacks see a valid lock.

Fixes: b888c510f7b3 ("igb: Avoid starting unnecessary workqueues")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: Codex:GPT-5
Signed-off-by: Runyu Xiao <runyu.xiao@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/igb/igb_ptp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 638d8242b..2a4ea327a 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -1378,6 +1378,7 @@ void igb_ptp_init(struct igb_adapter *adapter)
 		return;
 	}
 
+	spin_lock_init(&adapter->tmreg_lock);
 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
 						&adapter->pdev->dev);
 	if (IS_ERR(adapter->ptp_clock)) {
@@ -1388,7 +1389,6 @@ void igb_ptp_init(struct igb_adapter *adapter)
 			 adapter->netdev->name);
 		adapter->ptp_flags |= IGB_PTP_ENABLED;
 
-		spin_lock_init(&adapter->tmreg_lock);
 		INIT_WORK(&adapter->ptp_tx_work, igb_ptp_tx_work);
 
 		if (adapter->ptp_flags & IGB_PTP_OVERFLOW_CHECK)
-- 
2.34.1