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| author | Otavio Salvador <otavio@ossystems.com.br> | 2019-12-19 00:14:33 -0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-12-19 00:14:33 -0300 |
| commit | fa8a03bec68d9ef89da72277bd3501ed3daa6217 (patch) | |
| tree | 3d3218332bcb34cb0afa01d6ad996058a3dbcb77 /drivers/net/ethernet/intel/igb/igb_ptp.c | |
| parent | 6b774eec1f9d3064e9b33634dfa99d5666d0a73a (diff) | |
| parent | 1ddf624b0b268fdc0b80b1de618b98f8d117afea (diff) | |
Merge pull request #55 from toradex/4.14-2.0.x-imx
4.14 2.0.x imx
Diffstat (limited to 'drivers/net/ethernet/intel/igb/igb_ptp.c')
| -rw-r--r-- | drivers/net/ethernet/intel/igb/igb_ptp.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c index 0746b19ec6d3..295d27f33104 100644 --- a/drivers/net/ethernet/intel/igb/igb_ptp.c +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c @@ -65,9 +65,15 @@ * * The 40 bit 82580 SYSTIM overflows every * 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. */ -#define IGB_SYSTIM_OVERFLOW_PERIOD (HZ * 60 * 9) +#define IGB_SYSTIM_OVERFLOW_PERIOD (HZ * 60 * 8) #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) |