Fix PHY delay compensation math in igb_ptp_tx_hwtstamp() and
igb_ptp_rx_rgtstamp. Add PHY delay compensation in
igb_ptp_rx_pktstamp().
In the IGB driver, there are two functions that retrieve timestamps
received by the PHY - igb_ptp_rx_rgtstamp() and igb_ptp_rx_pktstamp().
The previous commit only changed igb_ptp_rx_rgtstamp(), and the change
was incorrect.
There are two instances in which PHY delay compensations should be
made:
- Before the packet transmission over the PHY, the latency between
when the packet is timestamped and transmission of the packets,
should be an add operation, but it is currently a subtract.
- After the packets are received from the PHY, the latency between
the receiving and timestamping of the packets should be a subtract
operation, but it is currently an add.
Signed-off-by: Kshitiz Gupta <kshitiz.gupta@ni.com>
Fixes: 3f544d2 (igb: adjust ptp timestamps for tx/rx latency)
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
0066c8b6f4