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

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Kever Yang <kever.yang@rock-chips.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	devicetree@vger.kernel.org, heiko@sntech.de,
	daniel.lezcano@linaro.org, linux-kernel@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	Rob Herring <robh+dt@kernel.org>,
	Jagan Teki <jagan@amarulasolutions.com>,
	Ezequiel Garcia <ezequiel@collabora.com>,
	linux-arm-kernel@lists.infradead.org,
	Akash Gajjar <akash@openedev.com>
Subject: Re: [PATCH 2/3] arm64: dts: rk3399-rock960: add vdd_log
Date: Wed, 13 Nov 2019 08:51:41 +0530	[thread overview]
Message-ID: <20191113032141.GB3377@Mani-XPS-13-9360> (raw)
In-Reply-To: <885996a6-e314-52c8-fec4-f66526dd1397@rock-chips.com>

Hi Kever,

On Wed, Nov 13, 2019 at 10:44:02AM +0800, Kever Yang wrote:
> 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.
> 

Hmm, okay. I will try to test these patches soon and share the observation here.

Thanks,
Mani

> 
> 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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