| Message ID | 1468653825-806-1-git-send-email-kshitiz.gupta@ni.com |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
> From: netdev-owner@vger.kernel.org [mailto:netdev- > owner@vger.kernel.org] On Behalf Of Kshitiz Gupta > Sent: Saturday, July 16, 2016 12:24 AM > To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; Nathan Sullivan > <nathan.sullivan@ni.com>; Brown, Aaron F <aaron.f.brown@intel.com> > Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; Kshitiz Gupta > <kshitiz.gupta@ni.com> > Subject: [PATCH] igb: fix adjusting ptp timestamps for tx/rx latency > > 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) > --- > drivers/net/ethernet/intel/igb/igb_ptp.c | 26 +++++++++++++++++++++++--- > 1 file changed, 23 insertions(+), 3 deletions(-) I think I was so engrossed in checking the values for 10 / 100 / 1000 delays that I completely missed the reversed add / subtract when looking at 3f544d2. Thanks for catching that. Tested-by: Aaron Brown <aaron.f.brown@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c index f097c5a..3c7bcdf 100644 --- 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 igb_adapter *adapter) } } - 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_vector *q_vector, 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_vector *q_vector, } } 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.
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) --- drivers/net/ethernet/intel/igb/igb_ptp.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)