On 2024-05-09 22:25:27 +0200, Andrew Lunn wrote:
> > +static void rtsn_set_delay_mode(struct rtsn_private *priv)
> > +{
> > + struct device_node *np = priv->ndev->dev.parent->of_node;
> > + u32 delay;
> > + u32 val;
> > +
> > + val = 0;
> > +
> > + /* The MAC is capable of applying a delay on both Rx and Tx. Each
> > + * delay can either be on or off, there is no way to set its length.
> > + *
> > + * The exact delay applied depends on electric characteristics of the
> > + * board. The datasheet describes a typical Rx delay of 1800 ps and a
> > + * typical Tx delay of 2000 ps.
> > + *
> > + * There are boards where the RTSN device is used together with PHYs
> > + * who do not support a large enough internal delays to function. These
> > + * boards depends on the MAC applying these inexact delays.
> > + */
> > +
> > + /* If the phy-mode is rgmii or rgmii-rxid apply Rx delay on the MAC */
> > + if (priv->iface == PHY_INTERFACE_MODE_RGMII_ID ||
> > + priv->iface == PHY_INTERFACE_MODE_RGMII_RXID)
> > + if (!of_property_read_u32(np, "rx-internal-delay-ps", &delay))
> > + if (delay)
> > + val |= GPOUT_RDM;
> > +
> > + /* If the phy-mode is rgmii or rgmii-txid apply Tx delay on the MAC */
> > + if (priv->iface == PHY_INTERFACE_MODE_RGMII_ID ||
> > + priv->iface == PHY_INTERFACE_MODE_RGMII_TXID)
> > + if (!of_property_read_u32(np, "tx-internal-delay-ps", &delay))
> > + if (delay)
> > + val |= GPOUT_TDM;
>
> Much better, but still not correct. rx-internal-delay-ps and
> tx-internal-delay-ps is meant for fine tuning the delays, generally in
> steps of a few 10ps. It is applied unconditionally, since it is just a
> fine tune.
>
> You hardware does not support fine tuning, just 1800/2000ps. So it
> makes no sense to use these DT properties. Just enable GPOUT_RDM or
> GPOUT_TDM as appropriate for PHY_INTERFACE_MODE_*.
I will address this and send a new version. Thanks for checking this.
>
> Andrew
>
> ---
> pw-bot: cr
--
Kind Regards,
Niklas Söderlund
