1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
index ddc6a4d19302..dcebd128becf 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
@@ -708,6 +708,7 @@ void ixgbe_ptp_start_cyclecounter(struct ixgbe_adapter *adapter)
 {
         struct ixgbe_hw *hw = &adapter->hw;
         u32 incval = 0;
+        u32 timinca = 0;
         u32 shift = 0;
         u32 cycle_speed;
         unsigned long flags;
@@ -730,8 +731,16 @@ void ixgbe_ptp_start_cyclecounter(struct ixgbe_adapter *adapter)
                 break;
         }
 
-        /* Bail if the cycle speed didn't change */
-        if (adapter->cycle_speed == cycle_speed)
+        /*
+         * grab the current TIMINCA value from the register so that it can be
+         * double checked. If the register value has been cleared, it must be
+         * reset to the correct value for generating a cyclecounter. If
+         * TIMINCA is zero, the SYSTIME registers do not increment at all.
+         */
+        timinca = IXGBE_READ_REG(hw, IXGBE_TIMINCA);
+
+        /* Bail if the cycle speed didn't change and TIMINCA is non-zero */
+        if (adapter->cycle_speed == cycle_speed && timinca)
                 return;
 
         /* disable the SDP clock out */