@@ -552,7 +552,7 @@ void igc_ptp_init(struct igc_adapter *adapter);
void igc_ptp_reset(struct igc_adapter *adapter);
void igc_ptp_suspend(struct igc_adapter *adapter);
void igc_ptp_stop(struct igc_adapter *adapter);
-void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
+void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
struct sk_buff *skb);
int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
@@ -154,46 +154,54 @@ static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
}
/**
- * igc_ptp_rx_pktstamp - retrieve Rx per packet timestamp
+ * igc_ptp_rx_pktstamp - Retrieve timestamp from rx packet buffer
* @q_vector: Pointer to interrupt specific structure
* @va: Pointer to address containing Rx buffer
* @skb: Buffer containing timestamp and packet
*
- * This function is meant to retrieve the first timestamp from the
- * first buffer of an incoming frame. The value is stored in little
- * endian format starting on byte 0. There's a second timestamp
- * starting on byte 8.
- **/
-void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
+ * This function retrieves the timestamp saved in the beginning of packet
+ * buffer. While two timestamps are available, one in timer0 reference and the
+ * other in timer1 reference, this function considers only the timestamp in
+ * timer0 reference.
+ */
+void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
struct sk_buff *skb)
{
struct igc_adapter *adapter = q_vector->adapter;
- __le64 *regval = (__le64 *)va;
- int adjust = 0;
-
- /* The timestamp is recorded in little endian format.
- * DWORD: | 0 | 1 | 2 | 3
- * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High
+ u64 regval;
+ int adjust;
+
+ /* Timestamps are saved in little endian at the beginning of the packet
+ * buffer following the layout:
+ *
+ * | 0 | 1 | 2 | 3 |
+ * | Timer1 SYSTIML | Timer1 SYSTIMH | Timer0 SYSTIML | Timer0 SYSTIMH |
+ *
+ * SYSTIML holds the nanoseconds part while SYSTIMH holds the seconds
+ * part of the timestamp.
*/
- igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
- le64_to_cpu(regval[0]));
-
- /* adjust timestamp for the RX latency based on link speed */
- if (adapter->hw.mac.type == igc_i225) {
- switch (adapter->link_speed) {
- case SPEED_10:
- adjust = IGC_I225_RX_LATENCY_10;
- break;
- case SPEED_100:
- adjust = IGC_I225_RX_LATENCY_100;
- break;
- case SPEED_1000:
- adjust = IGC_I225_RX_LATENCY_1000;
- break;
- case SPEED_2500:
- adjust = IGC_I225_RX_LATENCY_2500;
- break;
- }
+ regval = le32_to_cpu(va[2]);
+ regval |= (u64)le32_to_cpu(va[3]) << 32;
+ igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
+
+ /* Adjust timestamp for the RX latency based on link speed */
+ switch (adapter->link_speed) {
+ case SPEED_10:
+ adjust = IGC_I225_RX_LATENCY_10;
+ break;
+ case SPEED_100:
+ adjust = IGC_I225_RX_LATENCY_100;
+ break;
+ case SPEED_1000:
+ adjust = IGC_I225_RX_LATENCY_1000;
+ break;
+ case SPEED_2500:
+ adjust = IGC_I225_RX_LATENCY_2500;
+ break;
+ default:
+ adjust = 0;
+ netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");
+ break;
}
skb_hwtstamps(skb)->hwtstamp =
ktime_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
The comment describing the timestamps layout in the packet buffer is wrong and the code is actually retrieving the timestamp in Timer 1 reference instead of Timer 0. This hasn't been a big issue so far because hardware is configured to report both timestamps using Timer 0 (see IGC_SRRCTL register configuration in igc_ptp_enable_rx_timestamp() helper). This patch fixes the comment and the code so we retrieve the timestamp in Timer 0 reference as expected. This patch also takes the opportunity to get rid of the hw.mac.type check since it is not required. Fixes: 81b055205e8ba ("igc: Add support for RX timestamping") Signed-off-by: Andre Guedes <andre.guedes@intel.com> --- drivers/net/ethernet/intel/igc/igc.h | 2 +- drivers/net/ethernet/intel/igc/igc_ptp.c | 72 +++++++++++++----------- 2 files changed, 41 insertions(+), 33 deletions(-)