diff options
Diffstat (limited to 'drivers/net/ethernet/intel/e1000e/netdev.c')
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/netdev.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 6084e6ba45c..95cf482cf0a 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -4099,12 +4099,37 @@ static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc) struct e1000_adapter *adapter = container_of(cc, struct e1000_adapter, cc); struct e1000_hw *hw = &adapter->hw; - cycle_t systim; + cycle_t systim, systim_next; /* latch SYSTIMH on read of SYSTIML */ systim = (cycle_t)er32(SYSTIML); systim |= (cycle_t)er32(SYSTIMH) << 32; + if ((hw->mac.type == e1000_82574) || (hw->mac.type == e1000_82583)) { + u64 incvalue, time_delta, rem, temp; + int i; + + /* errata for 82574/82583 possible bad bits read from SYSTIMH/L + * check to see that the time is incrementing at a reasonable + * rate and is a multiple of incvalue + */ + incvalue = er32(TIMINCA) & E1000_TIMINCA_INCVALUE_MASK; + for (i = 0; i < E1000_MAX_82574_SYSTIM_REREADS; i++) { + /* latch SYSTIMH on read of SYSTIML */ + systim_next = (cycle_t)er32(SYSTIML); + systim_next |= (cycle_t)er32(SYSTIMH) << 32; + + time_delta = systim_next - systim; + temp = time_delta; + rem = do_div(temp, incvalue); + + systim = systim_next; + + if ((time_delta < E1000_82574_SYSTIM_EPSILON) && + (rem == 0)) + break; + } + } return systim; } |