From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Thu, 15 Jun 2017 09:16:57 +0000 (+0200)
Subject: ntp: apply HW TX/RX compensation to system time
X-Git-Tag: 3.2-pre1~52
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=db93180ce14a55abdc3c820129b0199142a1a050;p=thirdparty%2Fchrony.git

ntp: apply HW TX/RX compensation to system time

Apply the compensation to the cooked local time instead of HW time. This
might make a difference when the HW clock has a large frequency error.
---

diff --git a/ntp_io_linux.c b/ntp_io_linux.c
index 5a506773..736aea54 100644
--- a/ntp_io_linux.c
+++ b/ntp_io_linux.c
@@ -451,14 +451,14 @@ process_hw_timestamp(struct Interface *iface, struct timespec *hw_ts,
     UTI_AddDoubleToTimespec(hw_ts, rx_correction, hw_ts);
   }
 
-  if (!rx_ntp_length && iface->tx_comp)
-    UTI_AddDoubleToTimespec(hw_ts, iface->tx_comp, hw_ts);
-  else if (rx_ntp_length && iface->rx_comp)
-    UTI_AddDoubleToTimespec(hw_ts, -iface->rx_comp, hw_ts);
-
   if (!HCL_CookTime(iface->clock, hw_ts, &ts, &local_err))
     return;
 
+  if (!rx_ntp_length && iface->tx_comp)
+    UTI_AddDoubleToTimespec(&ts, iface->tx_comp, &ts);
+  else if (rx_ntp_length && iface->rx_comp)
+    UTI_AddDoubleToTimespec(&ts, -iface->rx_comp, &ts);
+
   ts_delay = UTI_DiffTimespecsToDouble(&local_ts->ts, &ts);
 
   if (fabs(ts_delay) > MAX_TS_DELAY) {