Re: [PATCH v2] net: fec: Add ECR bit macros, fix FEC_ECR_EN1588 being cleared on link-down

[Csókás Bence]

Hi!

On 6/10/24 21:13, Andrew Lunn wrote:
> On Fri, Jun 07, 2024 at 10:18:55AM +0200, Csókás, Bence wrote:
> > FEC_ECR_EN1588 bit gets cleared after MAC reset in `fec_stop()`, which
> > makes all 1588 functionality shut down on link-down. However, some
> > functionality needs to be retained (e.g. PPS) even without link.
>
> I don't know much about PPS. Could you point to some documentation,
> list email etc, which indicated PPS without link is expected to work.
>
> Please also Cc: Richard Cochran for changes like this.
>
> Thanks
> 	Andrew

This is what Richard said two years ago on the now-reverted patch:

Link: https://lore.kernel.org/netdev/YvRdTwRM4JBc5RuV@xxxxxxxxxxxxxxxxxx

> IMO the least surprising behavior is that once enabled, a feature
> stays on until explicitly disabled.

The point of PPS is, it is a 1 Hz clock reference. We don't want to take 
away a clock signal because of an unexpected link fault, for instance.

Plus, this patch doesn't even re-enable PPS or any other 1588 functions, 
it just prevents the adapter from forgetting it is even 1588-capable. 
I'll resubmit with more clear wording and appropriate "Fixes:" and "Cc:" 
tags.

Bence