ice/ptp: fix the PTP worker retrying indefinitely if the link went down

When the link goes down the ice_ptp_tx_tstamp() may loop re-trying to
process the packets till the 2 seconds timeout finally drops them.
In such a case it makes sense to just drop them right away.

Signed-off-by: Daniel Vacek <neelx@redhat.com>
Reviewed-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

@@ -680,6 +680,7 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 	struct ice_pf *pf;
 	struct ice_hw *hw;
 	u64 tstamp_ready;
+	bool link_up;
 	int err;
 	u8 idx;
 
@@ -695,11 +696,14 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 	if (err)
 		return false;
 
+	/* Drop packets if the link went down */
+	link_up = ptp_port->link_up;
+
 	for_each_set_bit(idx, tx->in_use, tx->len) {
 		struct skb_shared_hwtstamps shhwtstamps = {};
 		u8 phy_idx = idx + tx->offset;
 		u64 raw_tstamp = 0, tstamp;
-		bool drop_ts = false;
+		bool drop_ts = !link_up;
 		struct sk_buff *skb;
 
 		/* Drop packets which have waited for more than 2 seconds */
@@ -728,7 +732,7 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 		ice_trace(tx_tstamp_fw_req, tx->tstamps[idx].skb, idx);
 
 		err = ice_read_phy_tstamp(hw, tx->block, phy_idx, &raw_tstamp);
-		if (err)
+		if (err && !drop_ts)
 			continue;
 
 		ice_trace(tx_tstamp_fw_done, tx->tstamps[idx].skb, idx);