[Linux-stm32] [PATCH net-next 2/2] net: stmmac: Add Siflower SF19A2890 glue

[Andrew Lunn]

> +/* The MAC adds an RGMII delay only where the device tree asks for one */
> +static int sf19a2890_gmac_set_delays(struct sf19a2890_gmac *gmac)
> +{
> +	u32 tx, rx;
> +	int ret;
> +
> +	ret = sf19a2890_gmac_get_delay(gmac, "tx-internal-delay-ps", &tx);
> +	if (ret)
> +		return ret;
> +
> +	ret = sf19a2890_gmac_get_delay(gmac, "rx-internal-delay-ps", &rx);
> +	if (ret)
> +		return ret;
> +
> +	writel(tx, gmac->cfg + SF19A2890_GMAC_TX_DELAY);
> +	writel(rx, gmac->cfg + SF19A2890_GMAC_RX_DELAY);
> +	writel(!!rx, gmac->cfg + SF19A2890_GMAC_RX_DELAY_EN);

What does SF19A2890_GMAC_RX_DELAY_EN do? By default rx is 0, so the
delay is not enabled. Is that any different to actually enabling it
with SF19A2890_GMAC_RX_DELAY set to 0?

	Andrew