Re: [PATCH v4 3/3] phy: mediatek: tphy: add debugfs files

From: Andrew Lunn
Date: Sat Dec 03 2022 - 10:39:11 EST


On Sat, Dec 03, 2022 at 02:53:19PM +0000, Chunfeng Yun (云春峰) wrote:
> On Mon, 2022-11-28 at 15:00 +0100, Andrew Lunn wrote:
> > On Mon, Nov 28, 2022 at 07:26:02AM +0000, Chunfeng Yun (云春峰) wrote:
> > > On Thu, 2022-11-24 at 23:17 +0530, Vinod Koul wrote:
> > > > On 10-11-22, 21:27, Chunfeng Yun wrote:
> > > > > These debugfs files are mainly used to make eye diagram test
> > > > > easier,
> > > > > especially helpful to do HQA test for a new IC without efuse
> > > > > enabled.
> >
> > Exporting data for eye diagrams seems like something many PHYs could
> > use. Please consider adding an official uniform API which any PHY
> > could use, so we don't end up with lots of incompatible formats in
> > debugfs.
> Good idea, but it seems difficult to do it due to the settings of phy
> controllers are not common.

Do you have clear documentation about the values are exporting? Do you
have a documented procedure for the tests?

We need to collect together documentation from multiple vendors and
see what is common. Maybe nothing is common, maybe a lot is in common.
We won't know until we actually compare them.

I implemented cable testing for Ethernet PHYs. They are all different,
but actual give very similar results, so can have one common
description. How many different ways is there to make eye diagram
tests?

Andrew