Re: [PATCH net] net: stmmac: ptp: fix support for PTP_EXTTS_REQUEST2 ioctl

[Kory Maincent <kory.maincent@bootlin.com>]

On 11/4/26 06:25, James Clark wrote:
> Commit 7c571ac57d9d ("net: ptp: introduce .supported_extts_flags to
> ptp_clock_info") modified the PTP core to validate the supported flags
> of external timestamp requests, rather than relying on each driver to
> check them.
> 
> stmmac_enable() and dwmac1000_ptp_enable() ignore the flags, and
> neither stmmac_ptp_clock_ops nor dwmac1000_ptp_clock_ops was given any
> .supported_extts_flags. Since PTP_EXTTS_REQUEST2 always implies
> PTP_STRICT_FLAGS, the core now rejects every PTP_EXTTS_REQUEST2 for
> this driver with -EOPNOTSUPP, where before that commit the same
> requests succeeded. Only the PTP_EXTTS_REQUEST ioctl still works.
> 
> Tests on an NXP i.MX 8M Plus (FRDM-IMX8MPLUS, GMAC 5.10a) show that the
> auxiliary snapshot inputs timestamp just the rising edge. The reference
> manuals for the STM32MP13 (GMAC 4.20a) and the Cyclone V HPS (GMAC
> 3.70a, which uses dwmac1000_ptp_clock_ops) say the same.
> 
> Encode this in .supported_extts_flags. A PTP_EXTTS_REQUEST2 for the
> rising edge then succeeds, and one for the falling edge or for both
> edges fails with -EOPNOTSUPP.

Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>

Thank you!
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com