RE: [PATCH] igb: fix adjusting ptp timestamps for tx/rx latency

[Brown, Aaron F]

> From: netdev-ow...@vger.kernel.org [mailto:netdev-
> ow...@vger.kernel.org] On Behalf Of Kshitiz Gupta
> Sent: Saturday, July 16, 2016 12:24 AM
> To: Kirsher, Jeffrey T ; Nathan Sullivan
> ; Brown, Aaron F 
> Cc: intel-wired-...@lists.osuosl.org; netdev@vger.kernel.org; Kshitiz Gupta
> 
> 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 
> 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 

Re: [PATCH] igb: fix adjusting ptp timestamps for tx/rx latency

[kbuild test robot]

Hi,

[auto build test ERROR on jkirsher-next-queue/dev-queue]
[also build test ERROR on v4.7-rc7 next-20160715]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Kshitiz-Gupta/igb-fix-adjusting-ptp-timestamps-for-tx-rx-latency/20160716-062544
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git 
dev-queue
config: sparc64-allyesconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 5.3.1-8) 5.3.1 20160205
reproduce:
wget 
https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
 -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sparc64 

All errors (new ones prefixed by >>):

   drivers/net/ethernet/intel/igb/igb_ptp.c: In function 'igb_ptp_rx_pktstamp':
>> drivers/net/ethernet/intel/igb/igb_ptp.c:783:12: error: 'IGB_RX_LATENCY_10' 
>> undeclared (first use in this function)
  adjust = IGB_RX_LATENCY_10;
   ^
   drivers/net/ethernet/intel/igb/igb_ptp.c:783:12: note: each undeclared 
identifier is reported only once for each function it appears in
>> drivers/net/ethernet/intel/igb/igb_ptp.c:786:12: error: 'IGB_RX_LATENCY_100' 
>> undeclared (first use in this function)
  adjust = IGB_RX_LATENCY_100;
   ^
>> drivers/net/ethernet/intel/igb/igb_ptp.c:789:12: error: 
>> 'IGB_RX_LATENCY_1000' undeclared (first use in this function)
  adjust = IGB_RX_LATENCY_1000;
   ^

vim +/IGB_RX_LATENCY_10 +783 drivers/net/ethernet/intel/igb/igb_ptp.c

   777  igb_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
   778 le64_to_cpu(regval[1]));
   779  
   780  /* adjust timestamp for the RX latency based on link speed */
   781  switch (adapter->link_speed) {
   782  case SPEED_10:
 > 783  adjust = IGB_RX_LATENCY_10;
   784  break;
   785  case SPEED_100:
 > 786  adjust = IGB_RX_LATENCY_100;
   787  break;
   788  case SPEED_1000:
 > 789  adjust = IGB_RX_LATENCY_1000;
   790  break;
   791  }
   792  skb_hwtstamps(skb)->hwtstamp =

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


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