Subject: Re: [RFC 0/3] ptp: Add esterror support

From: Jakub Kicinski <[email-masked]>
Date: Wed, 14 Aug 2024 17:41:47 -0700

On Tue, 13 Aug 2024 12:55:59 +0000 Maciek Machnikowski wrote:
> This patch series implements handling of timex esterror field
> by ptp devices.
> 
> Esterror field can be used to return or set the estimated error
> of the clock. This is useful for devices containing a hardware
> clock that is controlled and synchronized internally (such as
> a time card) or when the synchronization is pushed to the embedded
> CPU of a DPU.
> 
> Current implementation of ADJ_ESTERROR can enable pushing
> current offset of the clock calculated by a userspace app
> to the device, which can act upon this information by enabling
> or disabling time-related functions when certain boundaries
> are not met (eg. packet launchtime)

Please do CC people who are working on the VM / PTP / vdso thing,
and time people like tglx. And an implementation for a real device
would be nice to establish attention.