diff options
| author | Todd Fujinaka <todd.fujinaka@intel.com> | 2014-05-03 06:41:37 +0000 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2014-05-27 02:09:57 -0700 |
| commit | 5e7ff970041321a26f2dc3aa41ba79e787fcf8f9 (patch) | |
| tree | 7e72236781a130581d00b17c738926975b79f2a3 /drivers/net | |
| parent | b3e5bf1ff32cbc58c56675498565020460c683cd (diff) | |
e1000e: 82574/82583 TimeSync errata for SYSTIM read
Due to a synchronization error, the value read from SYSTIML/SYSTIMH
might be incorrect.
Signed-off-by: Todd Fujinaka <todd.fujinaka@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/e1000.h | 2 | ||||
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/netdev.c | 27 |
2 files changed, 28 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h index e27e6091094..63bde99a4ab 100644 --- a/drivers/net/ethernet/intel/e1000e/e1000.h +++ b/drivers/net/ethernet/intel/e1000e/e1000.h @@ -391,6 +391,8 @@ s32 e1000e_get_base_timinca(struct e1000_adapter *adapter, u32 *timinca); * 25MHz 46-bit 2^46 / 10^9 / 3600 = 19.55 hours */ #define E1000_SYSTIM_OVERFLOW_PERIOD (HZ * 60 * 60 * 4) +#define E1000_MAX_82574_SYSTIM_REREADS 50 +#define E1000_82574_SYSTIM_EPSILON (1ULL << 35ULL) /* hardware capability, feature, and workaround flags */ #define FLAG_HAS_AMT (1 << 0) 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; } |