[PATCH] arm64: dts: meson: fix PHY deassert timing requirements

[Stefan Agner]

On 2021-04-07 16:29, Neil Armstrong wrote:
> On 07/04/2021 16:21, Stefan Agner wrote:
>> On 2021-04-07 15:31, Neil Armstrong wrote:
>>> Hi,
>>>
>>> On 06/04/2021 19:47, Stefan Agner wrote:
>>>> The sync of the device tree and dt-bindings from Linux v5.6-rc2
>>>> 11a48a5a18c6 ("Linux 5.6-rc2") causes Ethernet to break on some
>>>> ODROID-C2.
>>>>
>>>> Meanwhile a fix to increase the reset timing has been added to Linux.
>>>> Instead of reverting the offending commit, use the new reset timing
>>>> from upstream Linux commit c183c406c432 ("arm64: dts: meson: fix PHY
>>>> deassert timing requirements").
>>>>
>>>> Fixes: dd5f2351e99a ("arm64: dts: meson: sync dt and bindings from v5.6-rc2")
>>>> Signed-off-by: Stefan Agner <stefan at agner.ch>
>>>> ---
>>>>  arch/arm/dts/meson-g12b-odroid-n2.dtsi | 2 +-
>>>>  arch/arm/dts/meson-gxbb-nanopi-k2.dts  | 2 +-
>>>>  arch/arm/dts/meson-gxbb-odroidc2.dts   | 2 +-
>>>>  arch/arm/dts/meson-gxm-khadas-vim2.dts | 2 +-
>>>>  4 files changed, 4 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/arch/arm/dts/meson-g12b-odroid-n2.dtsi b/arch/arm/dts/meson-g12b-odroid-n2.dtsi
>>>> index 6982632ae6..39a09661c5 100644
>>>> --- a/arch/arm/dts/meson-g12b-odroid-n2.dtsi
>>>> +++ b/arch/arm/dts/meson-g12b-odroid-n2.dtsi
>>>> @@ -413,7 +413,7 @@
>>>>  		max-speed = <1000>;
>>>>
>>>>  		reset-assert-us = <10000>;
>>>> -		reset-deassert-us = <30000>;
>>>> +		reset-deassert-us = <80000>;
>>>
>>> In fact, these are not used by current U-boot, support for
>>> reset/deassert in PHY node
>>> is not yet supported in U-Boot. This first step was to switch to
>>> DM_MDIO and use the
>>> proper Designware glue, the second step is to find how to make use of
>>> these properties.
>>
>> Hm, that is strange, I have users reporting that this patch fixes the
>> issue on their devices. I guess it might be that the problem does not
>> always appear and it was just (bad) luck.
>>
>>>
>>> Concerning the patch, I'll prefer you sync the DT with v5.11 instead.
>>
>> We have multiple reports of non-working ODROID-C2 which worked in
>> previous U-Boot releases:
>> https://github.com/home-assistant/operating-system/issues/1202
>>
>> Similar reports exist in Armbian Forums as well.
>>
>> Until we have proper PHY reset/deassert support, I'd suggest to revert
>> dd5f2351e99a ("arm64: dts: meson: sync dt and bindings from v5.6-rc2")
>> partially then...
> 
> Reverting this is clearly not a solution, the intermediate solution is to
> put back the previous reset properties like it was done for multiple boards
> like in arch/arm/dts/meson-sm1-odroid-c4-u-boot.dtsi :

Yes, that is what I meant with revert ... partially. :)

I'll send a patch.

--
Stefan

> 
> ==========================================================================
> diff --git a/arch/arm/dts/meson-gxbb-odroidc2-u-boot.dtsi
> b/arch/arm/dts/meson-gxbb-odroidc2-u-boot.dtsi
> index 90087b00db..f1e6914351 100644
> --- a/arch/arm/dts/meson-gxbb-odroidc2-u-boot.dtsi
> +++ b/arch/arm/dts/meson-gxbb-odroidc2-u-boot.dtsi
> @@ -29,6 +29,12 @@
>         };
>  };
> 
> +&ethmac {
> +        snps,reset-gpio = <&gpio GPIOZ_14 0>;
> +        snps,reset-delays-us = <0 10000 1000000>;
> +        snps,reset-active-low;
> +};
> +
>  &usb0 {
>         status = "disabled";
>  };
> ==========================================================================
> 
> Neil
>>
>> --
>> Stefan
>>
>>
>>>
>>> Neil
>>>
>>>>  		reset-gpios = <&gpio GPIOZ_15 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
>>>>
>>>>  		interrupt-parent = <&gpio_intc>;
>>>> diff --git a/arch/arm/dts/meson-gxbb-nanopi-k2.dts b/arch/arm/dts/meson-gxbb-nanopi-k2.dts
>>>> index 7be3e35409..de27beafe9 100644
>>>> --- a/arch/arm/dts/meson-gxbb-nanopi-k2.dts
>>>> +++ b/arch/arm/dts/meson-gxbb-nanopi-k2.dts
>>>> @@ -165,7 +165,7 @@
>>>>  			reg = <0>;
>>>>
>>>>  			reset-assert-us = <10000>;
>>>> -			reset-deassert-us = <30000>;
>>>> +			reset-deassert-us = <80000>;
>>>>  			reset-gpios = <&gpio GPIOZ_14 GPIO_ACTIVE_LOW>;
>>>>
>>>>  			interrupt-parent = <&gpio_intc>;
>>>> diff --git a/arch/arm/dts/meson-gxbb-odroidc2.dts b/arch/arm/dts/meson-gxbb-odroidc2.dts
>>>> index 70fcfb7b06..50de1d01e5 100644
>>>> --- a/arch/arm/dts/meson-gxbb-odroidc2.dts
>>>> +++ b/arch/arm/dts/meson-gxbb-odroidc2.dts
>>>> @@ -200,7 +200,7 @@
>>>>  			reg = <0>;
>>>>
>>>>  			reset-assert-us = <10000>;
>>>> -			reset-deassert-us = <30000>;
>>>> +			reset-deassert-us = <80000>;
>>>>  			reset-gpios = <&gpio GPIOZ_14 GPIO_ACTIVE_LOW>;
>>>>
>>>>  			interrupt-parent = <&gpio_intc>;
>>>> diff --git a/arch/arm/dts/meson-gxm-khadas-vim2.dts b/arch/arm/dts/meson-gxm-khadas-vim2.dts
>>>> index bff8ec2c1c..e38d9e50ca 100644
>>>> --- a/arch/arm/dts/meson-gxm-khadas-vim2.dts
>>>> +++ b/arch/arm/dts/meson-gxm-khadas-vim2.dts
>>>> @@ -194,7 +194,7 @@
>>>>  		reg = <0>;
>>>>
>>>>  		reset-assert-us = <10000>;
>>>> -		reset-deassert-us = <30000>;
>>>> +		reset-deassert-us = <80000>;
>>>>  		reset-gpios = <&gpio GPIOZ_14 GPIO_ACTIVE_LOW>;
>>>>
>>>>  		interrupt-parent = <&gpio_intc>;
>>>>