Re: [PATCH 2/3] arm64: dts: rk3399-rock960: add vdd_log

[Kever Yang <kever.yang@rock-chips.com>]

Hi Manivannan,

On 2019/11/13 上午1:17, Manivannan Sadhasivam wrote:
> On Tue, Nov 12, 2019 at 04:10:17PM +0800, Kever Yang wrote:
>> On 2019/11/11 下午1:22, Manivannan Sadhasivam wrote:
>>> Hi Kever,
>>>
>>> On Mon, Nov 11, 2019 at 08:51:57AM +0800, Kever Yang wrote:
>>>> Add vdd_log node according to rock960 schematic V13.
>>>>
>>>> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
>>>> ---
>>>>
>>>>    arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi | 12 ++++++++++++
>>>>    1 file changed, 12 insertions(+)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi
>>>> index c7d48d41e184..73afee257115 100644
>>>> --- a/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi
>>>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi
>>>> @@ -76,6 +76,18 @@
>>>>    		regulator-always-on;
>>>>    		vin-supply = <&vcc5v0_sys>;
>>>>    	};
>>>> +
>>>> +	vdd_log: vdd-log {
>>>> +		compatible = "pwm-regulator";
>>>> +		pwms = <&pwm2 0 25000 1>;
>>>> +		regulator-name = "vdd_log";
>>>> +		regulator-always-on;
>>>> +		regulator-boot-on;
>>>> +		regulator-min-microvolt = <800000>;
>>>> +		regulator-max-microvolt = <1400000>;
>>>> +		regulator-init-microvolt = <950000>;
>>> The default value seems to be 0.9v as per both Rock960 and Ficus schematics.
>>
>> The default value is 0.9V when pwm-regulator is not enabled, and this
>> 'init-microvolt' suppose to set the
>>
>> init value when pwm-regulator is enabled. I set this to 950mV because Peter
>> report that he experience
>>
>> the system hang during Fedora boot  up, and update the vdd_log to 950mV can
>> fix the issue due to
>>
>> engineer measure on another rk3399 board puma-Q7.
>>
> okay. Previously we had post-boot hang issue on Rock960 Model A boards when the
> performance governor was set as default. So the vdd_log node was removed from
> the devicetree. Have you tested that case also?
>
> Here is the commit:
> 13682e524167 ("arm64: dts: rockchip: remove vdd_log from rock960 to fix a stability issues")


For rk3399, the kernel does not touch this regulator, it should be take 
care by bootloader.

So I think we need to update both U-Boot and kernel.


Thanks,

- Kever

>
> thanks,
> Mani
>> Thanks,
>>
>> - Kever
>>
>>> Other than that,
>>> Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>>>
>>> Thanks,
>>> Mani
>>>
>>>> +		vin-supply = <&vcc_sys>;
>>>> +	};
>>>>    };
>>>>    &cpu_l0 {
>>>> -- 
>>>> 2.17.1
>>>>
>>



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