Re: [PATCH] net: axiemac: use a phandle to reference pcs_phy

[Andrew Lunn <andrew@lunn.ch>]

On Wed, Mar 16, 2022 at 03:59:53PM +0800, Andy Chiu wrote:
> The `of_mdio_find_device()` would get a reference to `mdio_device` by
> a given device tree node. Thus, getting a reference to the internal
> PCS/PMA PHY by `lp->phy_node` is incorrect since "phy-handle" in the DT
> sould point to the external PHY. This incorrect use of "phy-hanlde"
> would cause a problem when the driver called `phylink_of_phy_connect()`,
> where it would use "phy-handle" in the DT to connect the external PHY.
> To fix it, we could add a phandle, "pcs-phy", in the DT so that it would
> point to the internal PHY. And the driver would get the correct address
> of PCS/PHY.
> 
> Fixes: 1a02556086fc (net: axienet: Properly handle PCS/PMA PHY for 1000BaseX mode)
> Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
> Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
> ---
>  drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> index 6fd5157f0a6d..293189aab4e6 100644
> --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> @@ -2073,12 +2073,15 @@ static int axienet_probe(struct platform_device *pdev)
>  	}
>  	if (lp->phy_mode == PHY_INTERFACE_MODE_SGMII ||
>  	    lp->phy_mode == PHY_INTERFACE_MODE_1000BASEX) {
> -		if (!lp->phy_node) {
> -			dev_err(&pdev->dev, "phy-handle required for 1000BaseX/SGMII\n");
> +		np = of_parse_phandle(pdev->dev.of_node, "pcs-phy", 0);

Other drivers call this pcs-handle. Please be consistent with them.

You also should update the binding document with this new property.

	Andrew