ACK: [SRU][N/P][PATCH v2 0/1] integrated I219-LM network adapter appears to be running too fast, causing synchronization issues when using the I219-LM PTP feature

[Wei-Lin Chang]

On Tue, Jul 08, 2025 at 09:02:09AM +0800, AceLan Kao wrote:
> From: "Chia-Lin Kao (AceLan)" <acelan.kao at canonical.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/2116072
> 
> [Impact]
> There is an issue on Dell Precision 3591 running. The PHC(PTP Hardware
> Clock) on the integrated I219-LM network adapter appears to be running
> too fast, causing synchronization issues when using the I219-LM PTP feature.
> 
> [Fix]
> Intel submits a patch to fix the clock issue which is included in v6.16-rc3
> 688a0d61b2d7 e1000e: set fixed clock frequency indication for Nahum 11 and Nahum 13
> 
> [Test]
> Installed linuxptp (Version 4.4+snap):
> $ sudo snap install --edge linuxptp
> 
> Run this command to do a sanity check of the PHC (resetting clock to 0.0
> time, waiting for 10 seconds, and then reading time. The time read back
> should be (roughly) 10 seconds):
> $ sudo linuxptp.phc-ctl enp0s31f6 freq 0 set 0.0 wait 10.0 get
> phc_ctl[1461.965]: adjusted clock frequency offset to 0.000000ppb
> phc_ctl[1461.965]: set clock time to 0.000000000 or Thu Jan 1 01:00:00 1970
> phc_ctl[1471.965]: process slept for 10.000000 seconds
> phc_ctl[1471.965]: clock time is 15.998421125 or Thu Jan 1 01:00:15 1970
> 
> The returned time should be around 10 seconds.
> Without the fix, it's around 16 seconds.
> 
> [Where problems could occur]
> Fixed the clock value, and ignore the value from the firmware on mtp, lnp,
> and ptp platforms.
> It won't introduce any issue, because the clock is alwyas 38.4MHz on those
> platforms.
> 
> v2. Fixed the subject line and fixed typo
> 
> Vitaly Lifshits (1):
>   e1000e: set fixed clock frequency indication for Nahum 11 and Nahum 13
> 
>  drivers/net/ethernet/intel/e1000e/netdev.c | 14 +++++++++++---
>  drivers/net/ethernet/intel/e1000e/ptp.c    |  8 +++++---
>  2 files changed, 16 insertions(+), 6 deletions(-)
> 
> -- 
> 2.43.0
> 
> 
> -- 
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Acked-by: Wei-Lin Chang <weilin.chang at canonical.com>