On 9/19/20 1:14 PM, Biju Das wrote: [...] >>> By looking at [1], only this driver is using writeext. >>> [1]https://elixir.bootlin.com/u-boot/v2020.10-rc4/A/ident/writeext >> >> git grep indicates a couple more sites where the writeext is called. >> But look into the KSZ9031 datasheet, that particular writeext call seems to >> be >> setting up RGMII Clock Pad Skew (MMD Address 2, Register 8), and I think >> there is a matching DT binding to set those up too, rxc-skew-ps and txc- >> skew-ps I think. > > Thanks for the pointers. I checked the configs[2] which uses renesas ravb > driver > and found that we are defining only rxc-skew-ps in all dts. > > since CONFIG DM_ETH is defined it is already picking the value corresponding > to "rxc-skew-ps". > > For txc-skew-ps anyway the value is default one. So we don't care.
Are you sure (0xf << 5) | 0x19 is the same as the default value of the clock pad skew register ? [...]