[Intel-wired-lan] [net-next v3 6/7] mlx5: reject unsupported external timestamp flags

[Jacob Keller]

Fix the mlx5 core PTP support to explicitly reject any future flags that
get added to the external timestamp request ioctl.

In order to maintain currently functioning code, this patch accepts all
three current flags. This is because the PTP_RISING_EDGE and
PTP_FALLING_EDGE flags have unclear semantics and each driver seems to
have interpreted them slightly differently.

Cc: Feras Daoud <ferasda at mellanox.com>
Cc: Eugenia Emantayev <eugenia at mellanox.com>
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
index cff6b60de304..9a40f24e3193 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
@@ -236,6 +236,12 @@ static int mlx5_extts_configure(struct ptp_clock_info *ptp,
 	if (!MLX5_PPS_CAP(mdev))
 		return -EOPNOTSUPP;
 
+	/* Reject requests with unsupported flags */
+	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
+				PTP_RISING_EDGE |
+				PTP_FALLING_EDGE))
+		return -EOPNOTSUPP;
+
 	if (rq->extts.index >= clock->ptp_info.n_pins)
 		return -EINVAL;
 
-- 
2.23.0.245.gf157bbb9169d