The new adjustment should be based on the base frequency, not the I40E_PTP_40GB_INCVAL in i40e_ptp_adjfine(). This issue was introduced in commit 3626a690b717 ("i40e: use mul_u64_u64_div_u64 for PTP frequency calculation"), and was fixed in commit 1060707e3809 ("ptp: introduce helpers to adjust by scaled parts per million"). However the latter is a new feature and hasn't been backported to the stable releases. This issue affects both v6.0 and v6.1 versions, and the v6.1 version is an LTS version. Fixes: 3626a690b717 ("i40e: use mul_u64_u64_div_u64 for PTP frequency calculation") Cc: <stable@xxxxxxxxxxxxxxx> # 6.1 Signed-off-by: Yajun Deng <yajun.deng@xxxxxxxxx> --- drivers/net/ethernet/intel/i40e/i40e_ptp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c index ffea0c9c82f1..97a9efe7b713 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c @@ -361,9 +361,9 @@ static int i40e_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) 1000000ULL << 16); if (neg_adj) - adj = I40E_PTP_40GB_INCVAL - diff; + adj = freq - diff; else - adj = I40E_PTP_40GB_INCVAL + diff; + adj = freq + diff; wr32(hw, I40E_PRTTSYN_INC_L, adj & 0xFFFFFFFF); wr32(hw, I40E_PRTTSYN_INC_H, adj >> 32); -- 2.25.1