Re: TJA1100 100Base-T1 PHY features via ethtool?

[Florian Fainelli <f.fainelli@gmail.com>]

On 08/13/2018 12:35 PM, Michael Grzeschik wrote:
> Hi David,
> 
> I use a special 100Base-T1 phy (NXP TJA1100 [1]) that has some features
> like:
> 
> - enabling/disabling test modes
> - fault detection
> - switching managed/autonomous mode
> - signal quality indication
> - ...
> 
> I already implemented the support of the features with the
> ethtool --get/set-phy-tunables features by adding ethtool_phy_tunables:
> 
> ETHTOOL_PHY_TEST_MODE
> ETHTOOL_PHY_FAULT_DETECTION
> ETHTOOL_PHY_MANAGED_MODE
> ETHTOOL_PHY_SIGNAL_QUALITY
> 
> Before posting my series I wanted to ensure that this is the preferred
> interface for those options.

The tunable interface is there, but is very limited. A few months ago, I
had started proposing an interface to support PHY test modes [1] (the
standard IEEE 802.3 defined ones) but a lot of it should now be migrated
to the work that Michal is doing on the conversion of ethtool to netlink
[2].

[1]: https://lkml.org/lkml/2018/4/27/1172
[2]: https://www.spinics.net/lists/netdev/msg516233.html

> 
> I found a series from 2016 [2] that implements the userspace part for
> the loopback feature of some phys, that did not get mainline so far
> which makes me wonder if ethtool is still the way to go.

ethtool is being converted to netlink, and that will be a much more
flexible interface to work with since it is basically easily extensible
(unlike the current ethtool + ioctl approach).

Back when the patches were proposed, we just had mild disagreement on
the loopback terminology being used, and then nothing happened.

> 
> [1] https://www.nxp.com/docs/en/data-sheet/TJA1100.pdf
> [2] https://www.spinics.net/lists/netdev/msg406614.html
> 
> Thanks,
> Michael
> 


-- 
Florian