RE: [PATCH net-next v3 2/2] net: ethernet: Add driver for Sunplus SP7021

From: Wells Lu 呂芳騰
Date: Thu Dec 02 2021 - 20:38:42 EST


Hi Andrew,

Thank you for explanation.


Best regards,
Wells Lu


> > Hi Andrew,
> >
> > Thank you for explanation.
> >
> > I'll add phy_support_asym_pause() after PHY connected next patch.
> >
> > I found some drivers call phy_set_max_speed() to set PHY speed to 100M
> > after PHY connected. Is that necessary?
>
> > From 'supported', PHY supports 10M/100M already.
>
> You need phy_set_max_speed() when it is possible to connect a 10/100 MAC to a 1G PHY. You
> sometime do this because a 1G PHY is cheaper than a 100M PHY. Unless limited, the PHY will
> advertise and could negotiate a 1G link, but the MAC could then not support it. If it is
> not physically possible to connect a 1G PHY to your MAC, you don't need to worry.
>
> > I also found some drivers call phy_start_aneg() after PHY started.
>
> It is not needed.
>
> Andrew