Re: [PATCH 0/3] Fix EEE support for MT7531 and MT7988 SoC switch

[Arınç ÜNAL]

On 24.03.2024 14:39, Russell King (Oracle) wrote:
> On Sun, Mar 24, 2024 at 12:47:08PM +0300, Arınç ÜNAL wrote:
> > I've tested with switch ports interfaces' tx-timer from 0 to 40, same
> > tx-timer for both interfaces. Loss is still there.
>
> EEE implementations tend to be a mess in the way drivers implement the
> API, so one can't at the moment rely on what ethtool says about the
> status. Sadly, this is what happens when driver authors are left to
> their own ends. :(
>
> > I suppose the MT7531 switch PHYs need calibration for EEE that is currently
> > missing from the mediatek-ge driver.
>
> EEE is quite simple from the software point of view. There is software
> negotiation of the modules that EEE supports, and then there is are
> one or more timers that affect the behaviour of EEE. The LPI timer is
> "how long the link needs to be idle for before _this_ end signals that
> it _can_ enter low power state". The link only enters low power state
> when *both* ends of the link signal that they can enter low power
> state.
>
> What calibration would be necessary?

Check out mt798x_phy_eee() on drivers/net/phy/mediatek-ge-soc.c.

Arınç