Commit fc9e5020 authored by Andre Guedes's avatar Andre Guedes Committed by Tony Nguyen
Browse files

igc: Fix igc_ptp_rx_pktstamp() 



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: 81b05520 ("igc: Add support for RX timestamping")
Signed-off-by: default avatarAndre Guedes <andre.guedes@intel.com>
Signed-off-by: default avatarVedang Patel <vedang.patel@intel.com>
Signed-off-by: default avatarJithu Joseph <jithu.joseph@intel.com>
Reviewed-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: default avatarDvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 9a4a1cdc

drivers/net/ethernet/intel/igc/igc.h

+1 −1
Original line number Diff line number Diff line
@@ -547,7 +547,7 @@ 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);

drivers/net/ethernet/intel/igc/igc_ptp.c

+40 −32
Original line number Diff line number Diff line
@@ -152,32 +152,37 @@ 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;

	u64 regval;

	int adjust;



	/* The timestamp is recorded in little endian format.

	 * DWORD: | 0          | 1           | 2          | 3

	 * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High

	/* 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]));

	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 */

	if (adapter->hw.mac.type == igc_i225) {

	/* Adjust timestamp for the RX latency based on link speed */

	switch (adapter->link_speed) {

	case SPEED_10:

		adjust = IGC_I225_RX_LATENCY_10;
@@ -191,7 +196,10 @@ void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va, 
	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);