Re: [PATCH v2 1/2] net: phy: realtek: Add rtl8211e rx/tx delays config

Serge Semin
2019-04-26T23:45:12Z

On Fri, Apr 26, 2019 at 11:40:50PM +0200, Andrew Lunn wrote:
> On Sat, Apr 27, 2019 at 12:21:11AM +0300, Serge Semin wrote:
> > There are two chip pins named TXDLY and RXDLY which actually adds the 2ns
> > delays to TXC and RXC for TXD/RXD latching. Alas this is the only
> > documented info regarding the RGMII timing control configurations the PHY
> > provides. It turns out the same settings can be setup via MDIO registers
> > hidden in the extension pages layout. Particularly the extension page 0xa4
> > provides a register 0x1c, which bits 1 and 2 control the described delays.
> > They are used to implement the "rgmii-{id,rxid,txid}" phy-mode.
> >
> > 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
> >
> > There is also a freebsd-folks discussion regarding this register:
> > https://reviews.freebsd.org/D13591
> >
> > 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
> >
> > Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
>
>
> Hi Serge
>
> Next time please include a patch 0 containing a cover note explaining
> the who series.
>

Sure as long as the patchset gets to be much bigger than two small
patches with an obvious reason to be merged.

> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
>

Thanks.)

-Sergey

> Andrew