Re: [PATCH net-next 2/2] net: phy: aquantia: allow forcing order of MDI pairs

[Andrew Lunn]

On Wed, Aug 21, 2024 at 05:18:44PM +0100, Daniel Golle wrote:
> On Wed, Aug 21, 2024 at 06:07:06PM +0200, Andrew Lunn wrote:
> > On Wed, Aug 21, 2024 at 01:46:50PM +0100, Daniel Golle wrote:
> > > Normally, the MDI reversal configuration is taken from the MDI_CFG pin.
> > > However, some hardware designs require overriding the value configured
> > > by that bootstrap pin. The PHY allows doing that by setting a bit which
> > > allows ignoring the state of the MDI_CFG pin and configuring whether
> > > the order of MDI pairs should be normal (ABCD) or reverse (DCBA).
> > > 
> > > Introduce two boolean properties which allow forcing either normal or
> > > reverse order of the MDI pairs from DT.
> > 
> > How does this interact with ethtool -s eth42 [mdix auto|on|off]
> > 
> > In general, you want mdix auto, so the two ends figure out how the
> > cable is wired and so it just works.
> 
> It looks like Aquantia only supports swapping pair (1,2) with pair (3,6)
> like it used to be for MDI-X on 100MBit/s networks.
> 
> When all 4 pairs are in use (for 1000MBit/s or faster) the link does not
> come up with pair order is not configured correctly, either using MDI_CFG
> pin or using the "PMA Receive Reserved Vendor Provisioning 1" register.
> 
> And yes, I did verify that Auto MDI-X is enabled in the
> "Autonegotiation Reserved Vendor Provisioning 1" register.

Is it possible to read the strap configuration?  All DT needs to
indicate is that the strap is inverted.

	Andrew