Re: [PATCH net-next 1/8] net: phy: add support for overclocked SGMII

Andrew Halaney
2024-06-20T19:42:47Z

On Wed, Jun 19, 2024 at 10:07:21PM GMT, Russell King (Oracle) wrote:
> On Wed, Jun 19, 2024 at 09:51:12PM +0200, Andrew Lunn wrote:
> > phylib supports out of band signalling, which is enough to make this
> > work, so long as two peers will actually establish a link because they
> > are sufficiently tolerant of what the other end is doing. Sometimes
> > they need a hint. Russell King has been working on this mess, and i'm
> > sure he will be along soon.
>
> ... and I'm rolling my eyes, wondering whether I will get time to
> finish the code that I started any time soon. I'll note that the more
> hacky code we end up merging, the harder it will become to solve this
> problem (and we already have several differing behaviours merged with
> 2500base-X already.)
>
> > What i expect will happen is you keep calling this 2500BaseX, without
> > in band signalling. You can look back in the netdev mailling list for
> > more details and those that have been here before you. It is always
> > good to search the history, otherwise you are just going to repeat it.
>
> That's where things start getting sticky, because at the moment,
> phylink expects 2500base-X to be like 1000base-X, and be a media
> interface mode rather than a MAC-to-PHY interface mode. This is partly
> what my patches will address if I can get around to finishing them -
> but at this point I really do not know when that will be.
>
> I still have the high priority work problem that I'm actively involved
> with. I may have three weeks holiday at the start of July (and I really
> need it right now!) Then, there's possibly quite a lot of down time in
> August because I'm having early cataract ops which will substantially
> change my eye sight. There's two possible outcomes from that. The best
> case is that in just over two weeks after the first op, I'll be able to
> read the screen without glasses. The worst case is that I have to wait
> a further two to three weeks to see my optometrist (assuming he has
> availability), and then wait for replacement lenses to be made up,
> fitted and the new glasses sent.
>
> So, I'm only finding the occasional time to be able to look at
> mainline stuff, and I don't see that changing very much until maybe
> September.
>
> At this point, I think we may as well give up and let people do
> whatever they want to do with 2500base-X (which is basically what we're
> already doing), and when they have compatibility problems... well...
> really not much we can do about that, and it will be way too late to
> try and sort the mess out.

I hope your holiday and operation go well Russell.

Pardon my ignorance, but I know of quite a few things you have in flight
and because of that I'm not entirely sure what specific patches you're
referring to above. Have those hit the list? I know you're cleaning
up stmmac's phylink/pcs usage, but I'm thinking that this is outside of
that series. Thanks in advance for helping me understand all that's in
progress around this mess of a topic!