From: Andre Guedes andre.guedes@intel.com
[ Upstream commit fc9e5020971d57d7d0b3fef9e2ab2108fcb5588b ]
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 Signed-off-by: Vedang Patel vedang.patel@intel.com Signed-off-by: Jithu Joseph jithu.joseph@intel.com Reviewed-by: Maciej Fijalkowski maciej.fijalkowski@intel.com Tested-by: Dvora Fuxbrumer dvorax.fuxbrumer@linux.intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/igc/igc.h | 2 +- drivers/net/ethernet/intel/igc/igc_ptp.c | 72 +++++++++++++----------- 2 files changed, 41 insertions(+), 33 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h index 35baae900c1f..6dca67d9c25d 100644 --- a/drivers/net/ethernet/intel/igc/igc.h +++ b/drivers/net/ethernet/intel/igc/igc.h @@ -545,7 +545,7 @@ 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, __le32 *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); diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c index ac0b9c85da7c..545f4d0e67cf 100644 --- a/drivers/net/ethernet/intel/igc/igc_ptp.c +++ b/drivers/net/ethernet/intel/igc/igc_ptp.c @@ -152,46 +152,54 @@ 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, __le32 *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: + * + * DWORD: | 0 | 1 | 2 | 3 | + * Field: | 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);