From a5a0fc0461c70047d7fd771499db1710e3630122 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Wed, 28 May 2014 07:21:47 +0000 Subject: [PATCH] ixgbe: change PTP NSECS_PER_SEC to IXGBE_PTP_PPS_HALF_SECOND The PPS signal is not correct, as it generates a one half HZ clock signal, as it only generates one level change per second. To generate a full clock, we need two level changes per second. Also, change the name of the #define, in order to prevent confusion between it and NSEC_PER_SEC which is not guaranteed to be a 64bit value. Signed-off-by: Jacob Keller Tested-by: Phil Schmitt Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c index 68f87ecb8a76..5fd4b5271f9a 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c @@ -98,9 +98,11 @@ #define IXGBE_OVERFLOW_PERIOD (HZ * 30) #define IXGBE_PTP_TX_TIMEOUT (HZ * 15) -#ifndef NSECS_PER_SEC -#define NSECS_PER_SEC 1000000000ULL -#endif +/* half of a one second clock period, for use with PPS signal. We have to use + * this instead of something pre-defined like IXGBE_PTP_PPS_HALF_SECOND, in + * order to force at least 64bits of precision for shifting + */ +#define IXGBE_PTP_PPS_HALF_SECOND 500000000ULL /** * ixgbe_ptp_setup_sdp @@ -146,8 +148,8 @@ static void ixgbe_ptp_setup_sdp(struct ixgbe_adapter *adapter) IXGBE_TSAUXC_SDP0_INT); /* clock period (or pulse length) */ - clktiml = (u32)(NSECS_PER_SEC << shift); - clktimh = (u32)((NSECS_PER_SEC << shift) >> 32); + clktiml = (u32)(IXGBE_PTP_PPS_HALF_SECOND << shift); + clktimh = (u32)((IXGBE_PTP_PPS_HALF_SECOND << shift) >> 32); /* * Account for the cyclecounter wrap-around value by @@ -158,8 +160,8 @@ static void ixgbe_ptp_setup_sdp(struct ixgbe_adapter *adapter) clock_edge |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIMH) << 32; ns = timecounter_cyc2time(&adapter->tc, clock_edge); - div_u64_rem(ns, NSECS_PER_SEC, &rem); - clock_edge += ((NSECS_PER_SEC - (u64)rem) << shift); + div_u64_rem(ns, IXGBE_PTP_PPS_HALF_SECOND, &rem); + clock_edge += ((IXGBE_PTP_PPS_HALF_SECOND - (u64)rem) << shift); /* specify the initial clock start time */ trgttiml = (u32)clock_edge; -- 2.20.1