Re: [PATCH v3] net: phy: add driver for Motorcomm yt8511 phy
From: Andrew Lunn
Date: Fri May 14 2021 - 10:52:37 EST
> > I also wonder about bits 15:12 of PHY EXT ODH: Delay and driver
> > strength CFG register.
>
> The default value *works*, and from an emi perspective we want the
> lowest strength single that is reliable.
I was not meaning signal strength, but Txc_delay_sel_fe,
selecte tx_clk_rgmii delay in chip which is used to latch txd_rgmii
in 100BT/10BTe mode. 150ps step. Default value 15 means about 2ns
clock delay compared to txd_rgmii in typical cornor.
[Typos courtesy of the datasheet, not me!]
This sounds like more RGMII delays. It seems like PHY EXT 0CH is about
1G mode, and PHY EXT 0DH is about 10/100 mode. I think you probably
need to set this bits as well. Have you tested against a link peer at
10 Half? 100 Full?
Andrew