Re: [PATCH net-next v3 2/2] net: ethernet: Add driver for Sunplus SP7021
From: Andrew Lunn <andrew@lunn.ch>
Date: 2021-12-02 19:04:07
Also in:
linux-devicetree, lkml
From: Andrew Lunn <andrew@lunn.ch>
Date: 2021-12-02 19:04:07
Also in:
linux-devicetree, lkml
On Thu, Dec 02, 2021 at 06:46:40PM +0000, Wells Lu 呂芳騰 wrote:
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