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| author | David S. Miller <davem@davemloft.net> | 2018-11-12 04:57:54 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-11-12 04:57:54 +0300 |
| commit | 2b9b7502dfcb6169dbf3359702953bf756b4e273 (patch) | |
| tree | 58ab22096d49de6a0e049cf1267edc34b82916dc /drivers/net/ethernet/intel/igb | |
| parent | 9206eb0bc5679d06d2f54b9db86fe2b9a55e07e4 (diff) | |
| parent | ccda4af0f4b92f7b4c308d3acc262f4a7e3affad (diff) | |
| download | linux-2b9b7502dfcb6169dbf3359702953bf756b4e273.tar.xz | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Diffstat (limited to 'drivers/net/ethernet/intel/igb')
| -rw-r--r-- | drivers/net/ethernet/intel/igb/igb_ptp.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c index 8c1833a157d3..fd3071f55bd3 100644 --- a/drivers/net/ethernet/intel/igb/igb_ptp.c +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c @@ -53,13 +53,15 @@ * 2^40 * 10^-9 / 60 = 18.3 minutes. * * SYSTIM is converted to real time using a timecounter. As - * timecounter_cyc2time() allows old timestamps, the timecounter - * needs to be updated at least once per half of the SYSTIM interval. - * Scheduling of delayed work is not very accurate, so we aim for 8 - * minutes to be sure the actual interval is shorter than 9.16 minutes. + * timecounter_cyc2time() allows old timestamps, the timecounter needs + * to be updated at least once per half of the SYSTIM interval. + * Scheduling of delayed work is not very accurate, and also the NIC + * clock can be adjusted to run up to 6% faster and the system clock + * up to 10% slower, so we aim for 6 minutes to be sure the actual + * interval in the NIC time is shorter than 9.16 minutes. */ -#define IGB_SYSTIM_OVERFLOW_PERIOD (HZ * 60 * 8) +#define IGB_SYSTIM_OVERFLOW_PERIOD (HZ * 60 * 6) #define IGB_PTP_TX_TIMEOUT (HZ * 15) #define INCPERIOD_82576 BIT(E1000_TIMINCA_16NS_SHIFT) #define INCVALUE_82576_MASK GENMASK(E1000_TIMINCA_16NS_SHIFT - 1, 0) |