commit a0077a9fa3fef18ab0890e79a367270c5ae5fe54
author Stefan Sørensen <stefan.sorensen@spectralink.com> Fri Jul 11 08:18:26 2014 +0200
committer David S. Miller <davem@davemloft.net> Fri Jul 11 14:05:15 2014 -0700
tree 62768c6201ebbb491d0b5f92add5fe1f2bcc9dfa
parent 5e6438db34d522ee1c78b5d4c1c35a4a3bbd5054

dp83640: Adjust ptp event timestamps

  Event timestamp values should be adjusted by 3*reference clock period +
  11 ns = 35 ns to compensate for input path and synchronization delays.

So subtract 35ns from event timestamps.

Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/dp83640.c

diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c
index 53bd1af..76fbd39 100644
--- a/drivers/net/phy/dp83640.c
+++ b/drivers/net/phy/dp83640.c
@@ -755,6 +755,9 @@
 	event.type = PTP_CLOCK_EXTTS;
 	event.timestamp = phy2txts(&dp83640->edata);
 
+	/* Compensate for input path and synchronization delays */
+	event.timestamp -= 35;
+
 	for (i = 0; i < N_EXT_TS; i++) {
 		if (ext_status & exts_chan_to_edata(i)) {
 			event.index = i;