Hi Jacob,
Thanks for your work.
On 2025-03-12 15:15:51 -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@xxxxxxxxx>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> ---
> drivers/net/ethernet/renesas/ravb_ptp.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/renesas/ravb_ptp.c b/drivers/net/ethernet/renesas/ravb_ptp.c
> index 6e4ef7af27bf31ab2aad8e06a65e0ede6046e3c0..b4365906669f3bd40953813e263aeaafd2e1eb70 100644
> --- a/drivers/net/ethernet/renesas/ravb_ptp.c
> +++ b/drivers/net/ethernet/renesas/ravb_ptp.c
> @@ -179,8 +179,7 @@ static int ravb_ptp_extts(struct ptp_clock_info *ptp,
> /* Reject requests with unsupported flags */
> if (req->flags & ~(PTP_ENABLE_FEATURE |
> PTP_RISING_EDGE |
> - PTP_FALLING_EDGE |
> - PTP_STRICT_FLAGS))
> + PTP_FALLING_EDGE))
> return -EOPNOTSUPP;
>
> if (req->index)
>
> --
> 2.48.1.397.gec9d649cc640
>
--
Kind Regards,
Niklas Söderlund
