igb: adjust PTP timestamps for Tx/Rx latency
Table 7-62 on page 338 of the i210 datasheet lists TX and RX latencies
for the various speeds the chip supports. To give better PTP timestamp
accuracy, adjust the timestamps by the amounts Intel gives based on
current link speed.
Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index fdb6dfd..f097c5a 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -722,11 +722,29 @@
struct e1000_hw *hw = &adapter->hw;
struct skb_shared_hwtstamps shhwtstamps;
u64 regval;
+ int adjust = 0;
regval = rd32(E1000_TXSTMPL);
regval |= (u64)rd32(E1000_TXSTMPH) << 32;
igb_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);
+ /* adjust timestamp for the TX latency based on link speed */
+ if (adapter->hw.mac.type == e1000_i210) {
+ switch (adapter->link_speed) {
+ case SPEED_10:
+ adjust = IGB_I210_TX_LATENCY_10;
+ break;
+ case SPEED_100:
+ adjust = IGB_I210_TX_LATENCY_100;
+ break;
+ case SPEED_1000:
+ adjust = IGB_I210_TX_LATENCY_1000;
+ break;
+ }
+ }
+
+ shhwtstamps.hwtstamp = ktime_sub_ns(shhwtstamps.hwtstamp, adjust);
+
skb_tstamp_tx(adapter->ptp_tx_skb, &shhwtstamps);
dev_kfree_skb_any(adapter->ptp_tx_skb);
adapter->ptp_tx_skb = NULL;
@@ -771,6 +789,7 @@
struct igb_adapter *adapter = q_vector->adapter;
struct e1000_hw *hw = &adapter->hw;
u64 regval;
+ int adjust = 0;
/* If this bit is set, then the RX registers contain the time stamp. No
* other packet will be time stamped until we read these registers, so
@@ -790,6 +809,23 @@
igb_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
+ /* adjust timestamp for the RX latency based on link speed */
+ if (adapter->hw.mac.type == e1000_i210) {
+ switch (adapter->link_speed) {
+ case SPEED_10:
+ adjust = IGB_I210_RX_LATENCY_10;
+ break;
+ case SPEED_100:
+ adjust = IGB_I210_RX_LATENCY_100;
+ break;
+ case SPEED_1000:
+ adjust = IGB_I210_RX_LATENCY_1000;
+ break;
+ }
+ }
+ skb_hwtstamps(skb)->hwtstamp =
+ ktime_add_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
+
/* Update the last_rx_timestamp timer in order to enable watchdog check
* for error case of latched timestamp on a dropped packet.
*/