This is a note to let you know that I've just added the patch titled
igb: fix adjusting PTP timestamps for Tx/Rx latency
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
igb-fix-adjusting-ptp-timestamps-for-tx-rx-latency.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0066c8b6f4050d7c57f6379d6fd4535e2f267f17 Mon Sep 17 00:00:00 2001
From: Kshitiz Gupta <kshitiz.gupta@xxxxxx>
Date: Sat, 16 Jul 2016 02:23:45 -0500
Subject: igb: fix adjusting PTP timestamps for Tx/Rx latency
From: Kshitiz Gupta <kshitiz.gupta@xxxxxx>
commit 0066c8b6f4050d7c57f6379d6fd4535e2f267f17 upstream.
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@xxxxxx>
Fixes: 3f544d2 (igb: adjust ptp timestamps for tx/rx latency)
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/intel/igb/igb_ptp.c | 26 +++++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -743,7 +743,8 @@ static void igb_ptp_tx_hwtstamp(struct i
}
}
- shhwtstamps.hwtstamp = ktime_sub_ns(shhwtstamps.hwtstamp, adjust);
+ shhwtstamps.hwtstamp =
+ ktime_add_ns(shhwtstamps.hwtstamp, adjust);
skb_tstamp_tx(adapter->ptp_tx_skb, &shhwtstamps);
dev_kfree_skb_any(adapter->ptp_tx_skb);
@@ -766,13 +767,32 @@ void igb_ptp_rx_pktstamp(struct igb_q_ve
struct sk_buff *skb)
{
__le64 *regval = (__le64 *)va;
+ struct igb_adapter *adapter = q_vector->adapter;
+ int adjust = 0;
/* The timestamp is recorded in little endian format.
* DWORD: 0 1 2 3
* Field: Reserved Reserved SYSTIML SYSTIMH
*/
- igb_ptp_systim_to_hwtstamp(q_vector->adapter, skb_hwtstamps(skb),
+ igb_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
le64_to_cpu(regval[1]));
+
+ /* 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_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
}
/**
@@ -824,7 +844,7 @@ void igb_ptp_rx_rgtstamp(struct igb_q_ve
}
}
skb_hwtstamps(skb)->hwtstamp =
- ktime_add_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
+ ktime_sub_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.
Patches currently in stable-queue which might be from kshitiz.gupta@xxxxxx are
queue-4.7/igb-fix-adjusting-ptp-timestamps-for-tx-rx-latency.patch
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