[PATCH net-next v2 10/15] ice: disable Tx timestamps while link is down

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Jacob Keller <jacob.e.keller@intel.com>

Introduce a new link_down field for the Tx tracker which indicates whether
the link is down for a given port.

Use this bit to prevent any Tx timestamp requests from starting while link
is down. This ensures that we do not try to start new timestamp requests
until after link has been restored.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 11 ++++++++++-
 drivers/net/ethernet/intel/ice/ice_ptp.h |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 481492d84e0e..dffcd50bac3f 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -613,7 +613,7 @@ ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx)
 {
 	lockdep_assert_held(&tx->lock);
 
-	return tx->init && !tx->calibrating;
+	return tx->init && !tx->calibrating && !tx->link_down;
 }
 
 /**
@@ -806,6 +806,8 @@ ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 	}
 
 	tx->init = 1;
+	tx->link_down = 0;
+	tx->calibrating = 0;
 
 	spin_lock_init(&tx->lock);
 
@@ -1396,6 +1398,13 @@ void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
 	/* Update cached link status for this port immediately */
 	ptp_port->link_up = linkup;
 
+	/* Set the link status of the Tx tracker. While link is down, all Tx
+	 * timestamp requests will be ignored.
+	 */
+	spin_lock(&ptp_port->tx.lock);
+	ptp_port->tx.link_down = !linkup;
+	spin_unlock(&ptp_port->tx.lock);
+
 	/* E810 devices do not need to reconfigure the PHY */
 	if (ice_is_e810(&pf->hw))
 		return;
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 0bfafaaab6c7..75dcab8e1124 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -119,6 +119,7 @@ struct ice_tx_tstamp {
  * @init: if true, the tracker is initialized;
  * @calibrating: if true, the PHY is calibrating the Tx offset. During this
  *               window, timestamps are temporarily disabled.
+ * @link_down: if true, the link is down and timestamp requests are disabled
  * @verify_cached: if true, verify new timestamp differs from last read value
  */
 struct ice_ptp_tx {
@@ -130,6 +131,7 @@ struct ice_ptp_tx {
 	u8 len;
 	u8 init : 1;
 	u8 calibrating : 1;
+	u8 link_down : 1;
 	u8 verify_cached : 1;
 };
 
-- 
2.35.1