RE: [PATCH net-next] r8152: modify rtl8152_set_speed function

From: Hayes Wang
Date: Tue Sep 03 2019 - 03:37:01 EST


Heiner Kallweit [mailto:hkallweit1@xxxxxxxxx]
> Sent: Tuesday, September 03, 2019 3:13 PM
[...]
> > Some of our chips support the feature of UPS. When satisfying certain
> > condition, the hw would recover the settings of speed. Therefore, I have
> > to record the settings of the speed, and set them to hw.
> >
> Not knowing the UPS feature in detail:
> In net-next I changed the software "PHY speed-down" implementation to
> be more generic. It stores the old advertised settings in a new
> phy_device member adv_old, and restores them in phy_speed_up().
> Maybe what you need is similar.

It is a feature about power saving. When some conditions are
satisfied, the power of PHY would be cut. And the hw would
restore the PHY settings including the speed automatically,
when leaving power saving mode.

Best Regards,
Hayes