mlx5: reject unsupported external timestamp flags
authorJacob Keller <jacob.e.keller@intel.com>
Thu, 14 Nov 2019 18:45:00 +0000 (10:45 -0800)
committerDavid S. Miller <davem@davemloft.net>
Fri, 15 Nov 2019 20:48:32 +0000 (12:48 -0800)
commit2e0645a00e25f7122cad6da57ce3cc855df49ddd
tree888a196ae49b798b9f610dbccf364500b5f6f549
parent6edd110b41d5aa63d29492eea637e4e344b5d71d
mlx5: reject unsupported external timestamp flags

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.

[ RC: I'm not 100% sure what this driver does, but if I'm not wrong it
      follows the dp83640:

  flags                                                 Meaning
  ----------------------------------------------------  --------------------------
  PTP_ENABLE_FEATURE                                    Time stamp rising edge
  PTP_ENABLE_FEATURE|PTP_RISING_EDGE                    Time stamp rising edge
  PTP_ENABLE_FEATURE|PTP_FALLING_EDGE                   Time stamp falling edge
  PTP_ENABLE_FEATURE|PTP_RISING_EDGE|PTP_FALLING_EDGE   Time stamp falling edge
]

Cc: Feras Daoud <ferasda@mellanox.com>
Cc: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c