[Intel-wired-lan] [net-next v3 5/7] igb: reject unsupported external timestamp flags

Richard Cochran richardcochran at gmail.com
Sat Oct 12 18:31:09 UTC 2019


On Thu, Sep 26, 2019 at 11:11:07AM -0700, Jacob Keller wrote:
> Fix the igb 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.

This HW always time stamps both edges:

  flags                                                 Meaning                   
  ----------------------------------------------------  -------------------------- 
  PTP_ENABLE_FEATURE                                    Time stamp both edges
  PTP_ENABLE_FEATURE|PTP_RISING_EDGE                    Time stamp both edges
  PTP_ENABLE_FEATURE|PTP_FALLING_EDGE                   Time stamp both edges
  PTP_ENABLE_FEATURE|PTP_RISING_EDGE|PTP_FALLING_EDGE   Time stamp both edges
 
> Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>

Reviewed-by: Richard Cochran <richardcochran at gmail.com>


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