tree c829a46d03c54c4aeb8782f81de390dd41e42300
parent 7d9465ebcc5d0e5ab0d7dd36d7147d31cc76fcaf
author Jacob Keller <jacob.e.keller@intel.com> 1573757098 -0800
committer David S. Miller <davem@davemloft.net> 1573850912 -0800

dp83640: reject unsupported external timestamp flags

Fix the dp83640 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.

For the record, the semantics of this driver are:

  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: Stefan Sørensen <stefan.sorensen@spectralink.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>