Re: [PATCH net 2/5] renesas: reject PTP_STRICT_FLAGS as unsupported

[Simon Horman <horms@kernel.org>]

On Tue, Mar 18, 2025 at 01:59:47PM +0000, Simon Horman wrote:
> + Shimoda-san
> 
> On Mon, Mar 10, 2025 at 03:16:37PM -0700, Jacob Keller wrote:
> > The ravb_ptp_extts() function checks the flags coming from the
> > PTP_EXTTS_REQUEST ioctl, to ensure that future flags are not accepted on
> > accident.
> > 
> > This was updated to 'honor' the PTP_STRICT_FLAGS in commit 6138e687c7b6
> > ("ptp: Introduce strict checking of external time stamp options.").
> > However, the driver does not *actually* validate the flags.
> > 
> > I originally fixed this driver to reject future flags in commit
> > 592025a03b34 ("renesas: reject unsupported external timestamp flags"). It
> > is still unclear whether this hardware timestamps the rising, falling, or
> > both edges of the input signal.
> > 
> > Accepting requests with PTP_STRICT_FLAGS is a bug, as this could lead to
> > users mistakenly assuming a request with PTP_RISING_EDGE actually
> > timestamps the rising edge only.
> > 
> > Reject requests with PTP_STRICT_FLAGS (and hence all PTP_EXTTS_REQUEST2
> > requests) until someone with access to the datasheet or hardware knowledge
> > can confirm the timestamping behavior and update this driver.
> > 
> > Fixes: 6138e687c7b6 ("ptp: Introduce strict checking of external time stamp options.")
> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> 
> Adding Shimoda-san who may be able to help coordinate a review if
> Niklas and Paul are unavailable for some reason.

Sorry for the noise. I now see that Niklas has reviewed v2.