Re: [PATCH v3 0/2] net: stmmac: correct MAC propagation delay

[Johannes Zink]

Hi Kurt,

On 8/2/23 12:10, Kurt Kanzenbach wrote:
> On Tue Aug 01 2023, Johannes Zink wrote:
> > ---
> > Changes in v3:
> > - work in Richard's review feedback. Thank you for reviewing my patch:
> >    - as some of the hardware may have no or invalid correction value
> >      registers: introduce feature switch which can be enabled in the glue
> >      code drivers depending on the actual hardware support
> >    - only enable the feature on the i.MX8MP for the time being, as the patch
> >      improves timing accuracy and is tested for this hardware
> > - Link to v2: https://lore.kernel.org/r/20230719-stmmac_correct_mac_delay-v2-1-3366f38ee9a6@xxxxxxxxxxxxxx
> >
> > Changes in v2:
> > - fix builds for 32bit, this was found by the kernel build bot
> > 	Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > 	Closes: https://lore.kernel.org/oe-kbuild-all/202307200225.B8rmKQPN-lkp@xxxxxxxxx/
> > - while at it also fix an overflow by shifting a u32 constant from macro by 10bits
> >    by casting the constant to u64
> > - Link to v1: https://lore.kernel.org/r/20230719-stmmac_correct_mac_delay-v1-1-768aa4d09334@xxxxxxxxxxxxxx
> >
> > ---
> > Johannes Zink (2):
> >        net: stmmac: correct MAC propagation delay
> >        net: stmmac: dwmac-imx: enable MAC propagation delay correction for i.MX8MP
>
> Tested on imx8mp <-> TSN Switch <-> x86 with i225:
>
> Before your patch:
>
> |ptp4l -i eth0 -f configs/gPTP.cfg --summary_interval=5 -m
> |ptp4l[139.274]: rms    9 max   27 freq +29264 +/-  13 delay   347 +/-   2
> |ptp4l[171.279]: rms   10 max   24 freq +29257 +/-  13 delay   344 +/-   2
> |ptp4l[203.283]: rms   10 max   24 freq +29254 +/-  13 delay   347 +/-   2
> |ptp4l[235.288]: rms    9 max   24 freq +29255 +/-  13 delay   346 +/-   1
> |ptp4l[267.292]: rms    9 max   28 freq +29257 +/-  13 delay   347 +/-   2
>
> After:
>
> |ptp4l -i eth0 -f configs/gPTP.cfg --summary_interval=5 -m
> |ptp4l[214.186]: rms    9 max   29 freq +28868 +/-  16 delay   326 +/-   2
> |ptp4l[246.190]: rms    8 max   22 freq +28902 +/-  15 delay   329 +/-   2
> |ptp4l[278.194]: rms    9 max   24 freq +28930 +/-  15 delay   325 +/-   1
> |ptp4l[310.199]: rms    9 max   25 freq +28956 +/-  15 delay   327 +/-   3
> |ptp4l[342.203]: rms    9 max   27 freq +28977 +/-  14 delay   327 +/-   1
>
> And the derived register values:
>
> |[   15.864016] KURT: PTP_TS_INGR_CORR_NS: 3147483248 PTP_TS_INGR_CORR_SNS: 0
> |[   15.870862] KURT: PTP_TS_EGR_CORR_NS: 400 PTP_TS_EGR_CORR_SNS: 0
> |[   20.000962] KURT: PTP_TS_INGR_CORR_NS: 3147483636 PTP_TS_INGR_CORR_SNS: 0
> |[   20.007809] KURT: PTP_TS_EGR_CORR_NS: 12 PTP_TS_EGR_CORR_SNS: 0
>
> So, seems to work:
>
> Tested-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx> # imx8mp

Thank you for testing!
Johannes

> Thanks,
> Kurt

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