Messages in this thread | | | Date | Fri, 26 Apr 2019 15:28:21 +0200 | From | Andrew Lunn <> | Subject | Re: [PATCH] net: phy: realtek: Add rtl8211e rx/tx delays config |
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On Fri, Apr 26, 2019 at 12:30:10PM +0300, Serge Semin wrote: > The hidden RGMII configs register utilization was found in the > rtl8211e U-boot driver: > https://elixir.bootlin.com/u-boot/v2019.01/source/drivers/net/phy/realtek.c#L99 > > It confirms that the register bits field must control the so called > configuration pins described in the table 12-13 of the official PHY > datasheet: > 8:6 = PHY Address > 5:4 = Auto-Negotiation > 3 = Interface Mode Select > 2 = RX Delay > 1 = TX Delay > 0 = SELRGV
> +static int rtl8211e_config_init(struct phy_device *phydev) > +{ > + int ret, oldpage; > + u16 val = 0; > + > + ret = genphy_config_init(phydev); > + if (ret < 0) > + return ret; > + > + /* enable TX/RX delay for rgmii-* modes, otherwise disable it */ > + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID) > + val = RTL8211E_TX_DELAY | RTL8211E_RX_DELAY; > + else if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID) > + val = RTL8211E_TX_DELAY; > + else if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID) > + val = RTL8211E_RX_DELAY;
Hi Serge
You need to look for PHY_INTERFACE_MODE_RGMII and disable the bits. For any other value, and in particular PHY_INTERFACE_MODE_NA, you should leave the bits alone.
As you found out, u-boot knows how to program these bits. There are probably boards out there which rely on u-boot doing this, and the PHY driver then not messing with the bits. The way to indicate it should not mess with the bits is to not have a phy-mode property in DT, which results in PHY_INTERFACE_MODE_NA.
Andrew
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