On Tue, Feb 20, 2024 at 03:57:38AM +0800, Yang Xiwen via B4 Relay wrote:
> From: Yang Xiwen <forbidden405@xxxxxxxxxxx>
>
> Register the sub MDIO bus if it is found. Also implement the internal
> PHY reset procedure as needed.
>
> Note it's unable to put the MDIO bus node outside of MAC controller
> (i.e. at the same level in the parent bus node). Because we need to
> control all clocks and resets in FEMAC driver due to the phy reset
> procedure. So the clocks can't be assigned to MDIO bus device, which is
> an essential resource for the MDIO bus to work.
>
> No backward compatibility is maintained since the only existing
> user(Hi3516DV300) has not received any updates from HiSilicon for about
> 8 years already. And till today, no mainline dts for this SoC is found.
> It seems unlikely that there are still existing mainline Hi3516DV300
> users. The effort to maintain the old binding seems gain a little.
>
> Signed-off-by: Yang Xiwen <forbidden405@xxxxxxxxxxx>
> ---
> drivers/net/ethernet/hisilicon/hisi_femac.c | 77 +++++++++++++++++++++++------
> 1 file changed, 61 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/ethernet/hisilicon/hisi_femac.c b/drivers/net/ethernet/hisilicon/hisi_femac.c
...
> @@ -826,15 +844,34 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
> priv->phy_reset_delays,
> DELAYS_NUM);
> if (ret)
> - goto out_disable_clk;
> + goto out_free_netdev;
> hisi_femac_phy_reset(priv);
> }
>
> + // Register the optional MDIO bus
> + for_each_available_child_of_node(node, mdio_np) {
> + if (of_node_name_prefix(mdio_np, "mdio")) {
> + priv->mdio_pdev = of_platform_device_create(mdio_np, NULL, dev);
> + of_node_put(mdio_np);
> + if (!priv->mdio_pdev) {
> + dev_err(dev, "failed to register MDIO bus device\n");
> + ret = -ENODEV;
> + goto out_free_netdev;
> + }
> + mdio_registered = true;
> + break;
> + }
> + of_node_put(mdio_np);
Sorry for not noticing this earlier.
I think that of_node_put() only needs to be called in the
case of terminating the loop (via break, goto, return, etc...).
But should not be called otherwise (when the loop cycles) as
for_each_available_child_of_node() calls of_node_put().
Flagged by Coccinelle.
> + }
> +
> + if (!mdio_registered)
> + dev_warn(dev, "MDIO subnode not found. This is usually a bug.\n");
> +
> phy = of_phy_get_and_connect(ndev, node, hisi_femac_adjust_link);
> if (!phy) {
> dev_err(dev, "connect to PHY failed!\n");
> ret = -ENODEV;
> - goto out_disable_clk;
> + goto out_unregister_mdio_bus;
> }
>
> phy_attached_print(phy, "phy_id=0x%.8lx, phy_mode=%s\n",
...
