On Fri, Mar 10, 2023 at 02:34:07PM +0100, Michael Walle wrote: > Yeah, but my problem right now is, that if this discussion won't find > any good solution, the lan8814 phy timestamping will find it's way > into an official kernel and then it is really hard to undo things. > > So, I'd really prefer to *first* have a discussion how to proceed > with the PHY timestamping and then add the lan8814 support, so > existing boards don't show a regressions. You don't mean LAN8814 but LAN8841, no? For the former, PTP support was added in commit ece19502834d ("net: phy: micrel: 1588 support for LAN8814 phy") - first present in v5.18. For the latter, it was commit cafc3662ee3f ("net: micrel: Add PHC support for lan8841"), and this one indeed is in the v6.3 release candidates. Assuming you can prove a regression, how about adding the PHY driver whitelist *without* the lan8841 as a patch to net.git? (blaming commit cafc3662ee3f ("net: micrel: Add PHC support for lan8841")). Doing this will effectively deactivate lan8841 PHY timestamping without reverting the code. Then, this PHY timestamping support could be activated back in net-next, based on some sort of explicit UAPI call.