Re: [PATCH net-next 2/2] net: stmmac: Add Siflower SF19A2890 glue
From: Andrew Lunn
Date: Wed Nov 04 2026 - 18:32:37 EST
> +/* 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