Re: [PATCH net-next v3 0/4] Improve phc2sys precision for mv88e6xxx switch in combination with imx6-fec

[David Miller]

From: Hubert Feurstein <h.feurstein@xxxxxxxxx>
Date: Tue, 20 Aug 2019 10:48:29 +0200

> From: Hubert Feurstein <h.feurstein@xxxxxxxxx>
> 
> Changelog:
>  v3: mv88e6xxx_smi_indirect_write: forward ptp_sts only on the last write
>      Copied Miroslav Lichvar because of PTP offset compensation patch
>  v2: Added patch for PTP offset compensation
>      Removed mdiobus_write_sts as there was no user
>      Removed ptp_sts_supported-boolean and introduced flags instead
> 
> With this patchset the phc2sys synchronisation precision improved to +/-555ns on
> an IMX6DL with an MV88E6220 switch attached.
> 
> This patchset takes into account the comments from the following discussions:
> - https://lkml.org/lkml/2019/8/2/1364
> - https://lkml.org/lkml/2019/8/5/169
> 
> Patch 01 adds the required infrastructure in the MDIO layer.
> Patch 02 adds additional PTP offset compensation.
> Patch 03 adds support for the PTP_SYS_OFFSET_EXTENDED ioctl in the mv88e6xxx driver.
> Patch 04 adds support for the PTP system timestamping in the imx-fec driver.

It looks like there is still some active discussion about these changes and
there will likely be another spin.