Re: [PATCH 4/5] arm64: dts: rockchip: fix gmac support for NanoPi R5S

[Jonas Karlman]

Hi Tianling,
On 2023-03-16 06:34, Tianling Shen wrote:
> Hi Vasily,
> 
> On Thu, Mar 16, 2023 at 8:16 AM Vasily Khoruzhick <anarsoul@xxxxxxxxx> wrote:
>>
>> On Wed, Mar 15, 2023 at 9:02 AM Tianling Shen <cnsztl@xxxxxxxxx> wrote:
>>>
>>> - Changed phy-mode to rgmii.
>>>
>>> - Fixed pull type in pinctrl for gmac0.
>>>
>>> - Removed duplicate properties in mdio node.
>>>   These properties are defined in the gmac0 node already.
>>>
>>> Signed-off-by: Tianling Shen <cnsztl@xxxxxxxxx>
>>> ---
>>>  arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dts | 7 ++-----
>>>  1 file changed, 2 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dts b/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dts
>>> index e9adf5e66529..2a1118f15c29 100644
>>> --- a/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dts
>>> +++ b/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dts
>>> @@ -57,7 +57,7 @@
>>>         assigned-clock-rates = <0>, <125000000>;
>>>         clock_in_out = "output";
>>>         phy-handle = <&rgmii_phy0>;
>>> -       phy-mode = "rgmii-id";
>>> +       phy-mode = "rgmii";
>>>         pinctrl-names = "default";
>>>         pinctrl-0 = <&gmac0_miim
>>>                      &gmac0_tx_bus2
>>> @@ -79,9 +79,6 @@
>>>                 reg = <1>;
>>>                 pinctrl-0 = <&eth_phy0_reset_pin>;
>>>                 pinctrl-names = "default";
>>> -               reset-assert-us = <10000>;
>>> -               reset-deassert-us = <50000>;
>>> -               reset-gpios = <&gpio0 RK_PC4 GPIO_ACTIVE_LOW>;
>>
>> Hmm, I don't see RK_PC4 being used anywhere else. gmac0 has RK_PC5 as
> 
> Yes, it's a typo, it should be RK_RC5.
> 
>> snsp,reset-gpio. So it essentially drops reset for the PHY. Is it
>> expected?
> 
> snsp,reset-gpio defined reset already, so we don't need to set it here again.
> 
> ---
> 
> snsp,reset-gpio is the legacy binding, but I still have no idea why
> reset-gpios doesn't work,
> the dwmac driver will fail to lookup phy:
> 
> [   10.398514] rk_gmac-dwmac fe2a0000.ethernet eth0: no phy found
> [   10.399061] rk_gmac-dwmac fe2a0000.ethernet eth0: __stmmac_open:
> Cannot attach to PHY (error: -19)
> 
> Any ideas would be appreciated.

Generic ethernet phy driver is not resetting the phy in the same way
that snsp,reset-gpio does, please see top two commits at [1].

I have been meaning to send that out as an RFC but I got stuck in a
u-boot rabbit hole, and I also do not know what the correct way to fix
this would be, so I played with both device tree and code changes.
Will prioritize this and send out a RFC later today.

[1] https://github.com/Kwiboo/linux-rockchip/commits/rk3568-eth-phy-reset

Regards,
Jonas

> 
> Thanks,
> Tianling.
> 
>>
>>>         };
>>>  };
>>>
>>> @@ -115,7 +112,7 @@
>>>  &pinctrl {
>>>         gmac0 {
>>>                 eth_phy0_reset_pin: eth-phy0-reset-pin {
>>> -                       rockchip,pins = <0 RK_PC4 RK_FUNC_GPIO &pcfg_pull_down>;
>>> +                       rockchip,pins = <0 RK_PC4 RK_FUNC_GPIO &pcfg_pull_up>;
>>>                 };
>>>         };
>>>
>>> --
>>> 2.17.1
>>>