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| author | Jacob Keller <jacob.e.keller@intel.com> | 2014-05-28 07:21:47 +0000 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2014-07-01 02:48:39 -0700 |
| commit | a5a0fc0461c70047d7fd771499db1710e3630122 (patch) | |
| tree | 473d939ff22fb69197c3ebd188bcd476e2b843e0 | |
| parent | aec653c43b0c55667355e26d7de1236bda9fb4e3 (diff) | |
| download | linux-a5a0fc0461c70047d7fd771499db1710e3630122.tar.gz linux-a5a0fc0461c70047d7fd771499db1710e3630122.tar.bz2 linux-a5a0fc0461c70047d7fd771499db1710e3630122.zip | |
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 <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
| -rw-r--r-- | drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c | 16 |
1 files 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; |