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

[Marek Szyprowski <m.szyprowski@samsung.com>]

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;
                 /* If it is not integrated_phy, clk_phy is optional */
                 if (bsp_priv->integrated_phy) {
                         if (ret)


 > ...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland