Re: [patch 00/24] timekeeping/ptp: Expand snapshot functionality

[Jacob Keller]

On 5/26/2026 10:13 AM, Thomas Gleixner wrote:
> Sorry for the large CC list, but changing the inner workings touches
> unfortunately a lot of places in one go.
> 
> PTP wants to grow new snapshot functionality, which provides not only the
> captured CLOCK* values, but also the underlying clocksource counter value.
> 
>    https://lore.kernel.org/20260515164033.6403-1-akiyano@xxxxxxxxxx
> 
> There was quite some discussion in seemingly related threads how to capture
> these values and how to provide core infrastructure so that driver writers
> have something to work with
> 
>    https://lore.kernel.org/20260514225842.110706-1-hramamurthy@xxxxxxxxxx
>    https://lore.kernel.org/20260520135207.37826-1-dwmw2@xxxxxxxxxxxxx
> 
> This series implements the timekeeping related mechanisms to:
> 
>      1) Capture CLOCK values along with the clocksource counter value for
>      	non-hardware based sampling
> 
>      2) Expanding the hardware cross time stamp mechanism to hand back the
>      	clocksource counter value, which was captured by the device, along
>      	with the related CLOCK values
> 
>      3) Adding AUX clock support to the hardware cross timestamping core
> 

Overall the series looks good to me. I made some comments while
reviewing but nothing major and I think mostly it was on interim code
that is removed by the end of the series.

Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>

> It's based on v7.1-rc2 and also available from git:
> 
>     git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git timekeeping-ptp-extend-v1
> 
> Thanks to David for rebasing his PTP/timekeeping work on top and providing
> feedback, fixes and testing.
> 
> Thanks,
> 
> 	tglx
> ---
>  arch/arm64/kvm/hyp_trace.c                          |    8 
>  arch/arm64/kvm/hypercalls.c                         |    6 
>  drivers/net/dsa/sja1105/sja1105_main.c              |    8 
>  drivers/net/ethernet/intel/ice/ice_ptp.c            |    5 
>  drivers/net/ethernet/intel/igc/igc.h                |    1 
>  drivers/net/ethernet/intel/igc/igc_ptp.c            |    4 
>  drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c |    4 
>  drivers/net/wireless/intel/iwlwifi/mld/ptp.c        |    5 
>  drivers/net/wireless/intel/iwlwifi/mvm/ptp.c        |    7 
>  drivers/pps/generators/pps_gen-dummy.c              |    6 
>  drivers/pps/generators/pps_gen_tio.c                |    6 
>  drivers/ptp/ptp_chardev.c                           |   18 +
>  drivers/ptp/ptp_ocp.c                               |   11 -
>  drivers/ptp/ptp_vmclock.c                           |   25 --
>  drivers/virtio/virtio_rtc_ptp.c                     |    2 
>  include/linux/pps_kernel.h                          |    8 
>  include/linux/ptp_clock_kernel.h                    |   15 -
>  include/linux/timekeeping.h                         |   54 ++---
>  kernel/time/timekeeping.c                           |  211 ++++++++++++--------
>  sound/hda/common/controller.c                       |    4 
>  20 files changed, 236 insertions(+), 172 deletions(-)