On Thu, Sep 26, 2024 at 08:23:12PM +0200, Andrew Lunn wrote: > > Regarding rx and tx internal delays, that same section in the manual > > doesn't specify what unit is represented by the delay_ctrl bit field in > > GMAC_RXCLK_DELAY_CTRL and GMAC_TXCLK_DELAY_CTRL. It is only 5 bits and > > a max value of 31 seems too small to represent picoseconds. The vendor > > kernel [2] uses properties named "rx-clk-delay" and "tx-clk-delay" but > > doesn't indicate any units. I see ti,dp83867.yaml adds vendor specific > > rx and tx delay properties so that is what I've now done in this series. > > Note: the hardware default value of 0 for delay_ctrl works okay for the > > TH1520 hardware that I have. > > I assume you are talking about RGMII delays here? > > Do you have a board which needs to set these delays? In general, linux > has the PHY provide the 2ns delay. You only need the MAC to add the > delays if a PHY is being used which cannot add the needed > delays. Occasionally you need to fine tune the delay, and the MAC > delays can then be interesting. But since you have no idea what the > units are, i would prefer to simply hard code it to 0, unless is it > really needed. > > Andrew Yes, this is for the RGMII delays. None of the TH1520 boards that I have seem to need this. The hardware reset value is 0 which seems to work okay. I'll remove these custom properties in the next revision. Thanks, Drew
