[PATCH] arm64: dts: rockchip: rock-3a: make ethernet work

Michael Riesch michael.riesch at wolfvision.net
Mon Jul 17 00:40:54 PDT 2023


Hi all,

In addition to what has been already said:

On 7/16/23 15:50, Jonas Karlman wrote:
> On 2023-07-15 06:49, FUKAUMI Naoki wrote:
>> hi,
>>
>> On 7/15/23 01:24, Jonas Karlman wrote:
>>> On 2023-07-14 17:46, Heiko Stuebner wrote:
>>>> Am Freitag, 14. Juli 2023, 08:30:27 CEST schrieb FUKAUMI Naoki:
>>>>> ethernet on Radxa ROCK 3A is not working by following error:
>>>>>
>>>>>   rk_gmac-dwmac fe010000.ethernet eth0: no phy at addr -1
>>>>>   rk_gmac-dwmac fe010000.ethernet eth0: stmmac_open: Cannot attach to PHY (error: -19)
>>>>>
>>>>> to fix this problem, align related properties with vendor kernel
>>>>>   https://github.com/radxa/kernel/blob/linux-5.10-gen-rkr4.1/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>>>
>>>>> Fixes: 22a442e6586c ("arm64: dts: rockchip: add basic dts for the radxa rock3 model a")
>>>>> Signed-off-by: FUKAUMI Naoki <naoki at radxa.com>
>>>>
>>>> There also is a second patch in the mix adding the gmac1_clkin
>>>> ef9f4b4a5020 ("arm64: dts: rockchip: Add support of external clock to ethernet node on Rock 3A SBC")
>>>>
>>>> And this patch does the exact opposite as the original nodes.
>>>> Can someone please mention board versions? Or did the gmac1 never
>>>> really work in the first place?

As far as I know all schematics versions state that the PHY produces the
clock (see the most recent schematics here:
https://dl.radxa.com/rock3/docs/hw/3a/ROCK-3A-V1.3-SCH.pdf)

Although using the internal MAC clock works as well, using the
gmac1_clkin is most probably the correct way.

>>> Ethernet have worked and probably still works booting with vendor U-Boot.
>>>
>>> However, when booting using mainline U-Boot the ethernet PHY is never
>>> initialized or reset due to lack of a ethernet gmac driver for rk35xx.
>>
>> surely I'm using mainline u-boot.

Ah, this might explain why I never experienced this issue: I am using
mainline barebox with GMAC support.

>>> With an early work-in-progress gmac driver the ethernet PHY is working
>>> same as with vendor U-Boot, and the ethernet PHY is identified.
>>>
>>> This revert from using reset-gpios to using the deprecated
>>> snps,reset-gpio is probably the wrong way forward.
>>>
>>> I suspect there is a bug in net/phy/mdio_device.c on how reset-gpios
>>> is asserted/deasserted, it works differently than how I would expect it
>>> to work, and also differs in how U-Boot handles reset-gpios.
>>>
>>> Some earlier findings regarding this reset issue:
>>> https://github.com/Kwiboo/linux-rockchip/compare/rk3568-eth-phy-reset~2...rk3568-eth-phy-reset
>>>
>>> Will try to get a proper patch/rfc out later this weekend or early next
>>> week after re-testing that on latest kernel.
>>
>> thank you so much for your awesome work!
> 
> Thanks, made some progress on tracking down the root cause.
> From what I have discovered so far there is a chicken-and-egg problem:
> 
> - phy needs to be reset or phy_id read back as 0xffffffff on mdio bus
> - phy device is not created because a valid phy_id is not read back
> - phy device needs to be created before it can be reset
> 
> Possible workarounds so far:
> - phy is reset in U-Boot
>   - very early work-in-progress at https://github.com/Kwiboo/u-boot-rockchip/commit/6ee80f9a895a32551cf30dd4252a4960ed80dfc9
> - phy is reset using mdio bus reset
>   - similar to old https://github.com/Kwiboo/linux-rockchip/commit/8597fcfa0c5c792dabb44a2db7b283c56c99ec6a
> - phy is reset using deprecated snps,reset-gpio
>   - similar to mdio bus reset

There was a similar discussion here:
https://lore.kernel.org/all/CAMdYzYo_DGiO0UxJEb3xues7Um=X9AgPvz+Xp_YWb9pp9HaScg@mail.gmail.com/

The approach that moves the reset to the MDIO bus has been mentioned
there as well. On the first glance this approach looks reasonable to me.

Best regards,
Michael

> [...]
>>>>> ---
>>>>>   .../boot/dts/rockchip/rk3568-rock-3a.dts      | 32 ++++++-------------
>>>>>   1 file changed, 10 insertions(+), 22 deletions(-)
>>>>>
>>>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts b/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>>> index 917f5b2b8aab..f9381ab9629b 100644
>>>>> --- a/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>>> +++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>>> @@ -32,13 +32,6 @@ hdmi_con_in: endpoint {
>>>>>   		};
>>>>>   	};
>>>>>   
>>>>> -	gmac1_clkin: external-gmac1-clock {
>>>>> -		compatible = "fixed-clock";
>>>>> -		clock-frequency = <125000000>;
>>>>> -		clock-output-names = "gmac1_clkin";
>>>>> -		#clock-cells = <0>;
>>>>> -	};
>>>>> -
>>>>>   	leds {
>>>>>   		compatible = "gpio-leds";
>>>>>   
>>>>> @@ -256,18 +249,24 @@ &cpu3 {
>>>>>   
>>>>>   &gmac1 {
>>>>>   	assigned-clocks = <&cru SCLK_GMAC1_RX_TX>, <&cru SCLK_GMAC1>;
>>>>> -	assigned-clock-parents = <&cru SCLK_GMAC1_RGMII_SPEED>, <&gmac1_clkin>;
>>>>> -	clock_in_out = "input";
>>>>> +	assigned-clock-parents = <&cru SCLK_GMAC1_RGMII_SPEED>;
>>>>> +	assigned-clock-rates = <0>, <125000000>;
>>>>> +	clock_in_out = "output";
>>>>>   	phy-handle = <&rgmii_phy1>;
>>>>> -	phy-mode = "rgmii-id";
>>>>> +	phy-mode = "rgmii";
>>>>>   	phy-supply = <&vcc_3v3>;
>>>>>   	pinctrl-names = "default";
>>>>>   	pinctrl-0 = <&gmac1m1_miim
>>>>>   		     &gmac1m1_tx_bus2
>>>>>   		     &gmac1m1_rx_bus2
>>>>>   		     &gmac1m1_rgmii_clk
>>>>> -		     &gmac1m1_clkinout
>>>>>   		     &gmac1m1_rgmii_bus>;
>>>>> +	snps,reset-gpio = <&gpio3 RK_PB0 GPIO_ACTIVE_LOW>;
>>>>> +	snps,reset-active-low;
>>>>> +	/* Reset time is 20ms, 100ms for rtl8211f */
>>>>> +	snps,reset-delays-us = <0 20000 100000>;
>>>>> +	tx_delay = <0x42>;
>>>>> +	rx_delay = <0x28>;
>>>>>   	status = "okay";
>>>>>   };
>>>>>   
>>>>> @@ -588,11 +587,6 @@ &mdio1 {
>>>>>   	rgmii_phy1: ethernet-phy at 0 {
>>>>>   		compatible = "ethernet-phy-ieee802.3-c22";
>>>>>   		reg = <0x0>;
>>>>> -		pinctrl-names = "default";
>>>>> -		pinctrl-0 = <&eth_phy_rst>;
>>>>> -		reset-assert-us = <20000>;
>>>>> -		reset-deassert-us = <100000>;
>>>>> -		reset-gpios = <&gpio3 RK_PB0 GPIO_ACTIVE_LOW>;
>>>>>   	};
>>>>>   };
>>>>>   
>>>>> @@ -630,12 +624,6 @@ vcc_mipi_en: vcc_mipi_en {
>>>>>   		};
>>>>>   	};
>>>>>   
>>>>> -	ethernet {
>>>>> -		eth_phy_rst: eth_phy_rst {
>>>>> -			rockchip,pins = <3 RK_PB0 RK_FUNC_GPIO &pcfg_pull_none>;
>>>>> -		};
>>>>> -	};
>>>>> -
>>>>>   	hym8563 {
>>>>>   		hym8563_int: hym8563-int {
>>>>>   			rockchip,pins = <0 RK_PD3 RK_FUNC_GPIO &pcfg_pull_up>;
>>>>>
> 



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