Messages in this thread | | | Subject | Re: [PATCH v3 02/11] net: phy: Add 1000BASE-KX interface mode | From | Sean Anderson <> | Date | Thu, 18 Aug 2022 13:28:19 -0400 |
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On 8/18/22 1:12 PM, Vladimir Oltean wrote: > On Thu, Aug 18, 2022 at 01:03:54PM -0400, Sean Anderson wrote: >> Well, I suppose the real reason is that this will cause a merge conflict >> (or lack of one), since this series introduces phylink_interface_max_speed >> in patch 7, which is supposed to contain all the phy modes. So depending on >> what gets merged first, the other series will have to be modified and resent. >> >> To be honest, I had expected that trivial patches like that would have been >> applied and merged already. > > There's nothing trivial about this patch.
Perhaps "limited in scope and mostly independent" is better, then.
> 1000Base-KX is not a phy-mode > in exactly the same way that 1000Base-T isn't, either.
It has different AN from 1000BASE-X (c73 vs c37), and doesn't support half duplex. This is something the serdes and PCS have to care about. Unfortunately, we don't have a separate PCS_INTERFACE_MODE so these things become PHY_INTERFACE_MODEs.
> If you want to > bring PHY_INTERFACE_MODE_10GKR as a "yes, but" counterexample, it was > later clarified that 10gbase-r was what was actually meant in that case, > and we keep 10gbase-kr as phy-mode only for compatibility with some > device trees.
That's not what's documented:
> ``PHY_INTERFACE_MODE_10GBASER`` > This is the IEEE 802.3 Clause 49 defined 10GBASE-R protocol used with > various different mediums. Please refer to the IEEE standard for a > definition of this. > > Note: 10GBASE-R is just one protocol that can be used with XFI and SFI. > XFI and SFI permit multiple protocols over a single SERDES lane, and > also defines the electrical characteristics of the signals with a host > compliance board plugged into the host XFP/SFP connector. Therefore, > XFI and SFI are not PHY interface types in their own right. > > ``PHY_INTERFACE_MODE_10GKR`` > This is the IEEE 802.3 Clause 49 defined 10GBASE-R with Clause 73 > autonegotiation. Please refer to the IEEE standard for further > information. > > Note: due to legacy usage, some 10GBASE-R usage incorrectly makes > use of this definition.
so indeed you get a new phy interface mode when you add c73 AN. The clarification only applies to *incorrect* usage.
> I'd suggest resolving the merge conflict without 1000Base-KX and > splitting off a separate discussion about this topic. Otherwise it will > unnecessarily detract from PAUSE-based rate adaptation.
Well, no one is using it yet, so hopefully it will not be a problem...
--Sean
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