Re: [PATCH net-next v1 1/1] net: phy: dp83tg720: Add cable testing support

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Wed, Aug 07, 2024 at 03:24:52PM +0200, Andrew Lunn wrote:
> On Wed, Aug 07, 2024 at 11:32:51AM +0200, Oleksij Rempel wrote:
> > Introduce cable testing support for the DP83TG720 PHY. This implementation
> > is based on the "DP83TG720S-Q1: Configuring for Open Alliance Specification
> > Compliance (Rev. B)" application note.
> 
> Does the OA specification describe all these registers?

Not all of them.

OA specification provide recommendation for the bit layout for the TDR
status register (HDD.TDR):
https://opensig.org/wp-content/uploads/2024/03/Advanced_PHY_features_for_automotive_Ethernet_v2.0_fin.pdf

> Should we expect other devices to be identical?

Yes. I'll create a new file for OA specific helpers.

> > +/**
> > + * dp83tg720_get_fault_type - Convert TDR fault type to ethtool result code.
> > + * @fault_type: Fault type value from the PHY.
> > + *
> > + * Returns: Corresponding ethtool result code.
> > + */
> > +static int dp83tg720_get_fault_type(int fault_type)
> > +{
> > +	switch (fault_type) {
> > +	case DP83TG720S_TDR_FAULT_TYPE_SHORT:
> > +		return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;
> > +	case DP83TG720S_TDR_FAULT_TYPE_OPEN:
> > +		return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;
> > +	case DP83TG720S_TDR_FAULT_TYPE_NOISE:
> > +		return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;
> 
> You could add a new type for this. I think some implementations will
> also re-try a few times to see if a quiet period can be found.

ack.

Regards,
Oleksij
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