According the CYCLON V documention only the bit 16 of snaptypesel should set. (more information see Table 17-20 (cv_5v4.pdf) : Timestamp Snapshot Dependency on Register Bits) Fixes: d2042052a0aa ("stmmac: update the PTP header file") Signed-off-by: Mario Molitor <mario_molitor@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>