Re: [PATCH RFC net-next] net: phy: add Marvell PHY PTP support [multicast/DSA issues]

["Köry Maincent" <kory.maincent@bootlin.com>]

On Mon, 27 Feb 2023 15:20:05 +0000
"Russell King (Oracle)" <linux@armlinux.org.uk> wrote:

> > I see this patch has been abandoned.
> > I am testing it with a ZynqMP board (macb ethernet) and it seems to more or
> > less work. It got tx timestamp timeout at initialization but after some
> > times (~20 seconds) ptp4l manages to set it working. Also the IEEE 802.3
> > network PTP mode is not working, it constantly throw rx timestamp overrun
> > errors.
> > I will aim at fixing these issues and adding support to interrupts. It
> > would be good to have it accepted mainline. What do you think is missing
> > for that?  
> 
> It isn't formally abandoned, but is permanently on-hold as merging
> Marvell PHY PTP support into mainline _will_ regress the superior PTP
> support on the Macchiatobin platform for the reasons outlined in:
> 
> https://lore.kernel.org/netdev/20200729220748.GW1605@shell.armlinux.org.uk/
> 
> Attempting to fix this problem was basically rejected by the PTP
> maintainer, and thus we're at a deadlock over the issue, and Marvell
> PHY PTP support can never be merged into mainline.

As I understand, if the PHY support PTP, it is prioritize to the PTP of the MAC.
As quote in the mail thread it seems there was discussion in netdev about
moving phy_has_hwtstamp to core and allowing ethtool to choose which one to
use. I don't know if the decision have been made about it since, but it seems
nothing has been sent to mainline. Meanwhile, why do we not move forward on
this patch with the current PTP behavior and updates it when new core PTP change
will be sent mailine?

Regards,
Köry