Re: [PATCH net-next v3] net: ethernet: stmmac: dwmac-rk: Make the clk_phy could be used for external phy

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Mon, Aug 25, 2025 at 12:53:37PM +0200, Marek Szyprowski wrote:
> On 25.08.2025 11:57, Chaoyi Chen wrote:
> > On 8/25/2025 3:23 PM, Marek Szyprowski wrote:
> >> On 15.08.2025 04:35, Chaoyi Chen wrote:
> >>> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
> >>>
> >>> For external phy, clk_phy should be optional, and some external phy
> >>> need the clock input from clk_phy. This patch adds support for setting
> >>> clk_phy for external phy.
> >>>
> >>> Signed-off-by: David Wu <david.wu@rock-chips.com>
> >>> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
> >>> ---
> >>>
> >>> Changes in v3:
> >>> - Link to V2: 
> >>> https://lore.kernel.org/netdev/20250812012127.197-1-kernel@airkyi.com/
> >>> - Rebase to net-next/main
> >>>
> >>> Changes in v2:
> >>> - Link to V1: 
> >>> https://lore.kernel.org/netdev/20250806011405.115-1-kernel@airkyi.com/
> >>> - Remove get clock frequency from DT prop
> >>>
> >>>    drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c | 11 +++++++----
> >>>    1 file changed, 7 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c 
> >>> b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> >>> index ac8288301994..5d921e62c2f5 100644
> >>> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> >>> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> >>> @@ -1412,12 +1412,15 @@ static int rk_gmac_clk_init(struct 
> >>> plat_stmmacenet_data *plat)
> >>>            clk_set_rate(plat->stmmac_clk, 50000000);
> >>>        }
> >>>    -    if (plat->phy_node && bsp_priv->integrated_phy) {
> >>> +    if (plat->phy_node) {
> >>>            bsp_priv->clk_phy = of_clk_get(plat->phy_node, 0);
> >>>            ret = PTR_ERR_OR_ZERO(bsp_priv->clk_phy);
> >>> -        if (ret)
> >>> -            return dev_err_probe(dev, ret, "Cannot get PHY clock\n");
> >>> -        clk_set_rate(bsp_priv->clk_phy, 50000000);
> >>> +        /* If it is not integrated_phy, clk_phy is optional */
> >>> +        if (bsp_priv->integrated_phy) {
> >>> +            if (ret)
> >>> +                return dev_err_probe(dev, ret, "Cannot get PHY 
> >>> clock\n");
> >>> +            clk_set_rate(bsp_priv->clk_phy, 50000000);
> >>> +        }
> >
> > I think  we should set bsp_priv->clk_phy to NULL here if we failed to 
> > get the clock.
> >
> > Could you try this on your board? Thank you.
> 
> Right, the following change also fixes this issue:
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c 
> b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> index 9fc41207cc45..2d19d48be01f 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> @@ -1415,6 +1415,8 @@ static int rk_gmac_clk_init(struct 
> plat_stmmacenet_data *plat)
>          if (plat->phy_node) {
>                  bsp_priv->clk_phy = of_clk_get(plat->phy_node, 0);
>                  ret = PTR_ERR_OR_ZERO(bsp_priv->clk_phy);
> +               if (ret)
> +                       bsp_priv->clk_phy = NULL;

Or just:

		clk = of_clk_get(plat->phy_node, 0);
		if (clk == ERR_PTR(-EPROBE_DEFER))
			...
		else if (!IS_ERR)
			bsp_priv->clk_phy = clk;

I don't have a free terminal to work out what "..." should be.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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