[PATCH v1] arm64: dts: rockchip: remove vdd_log from rk3399-puma

[PATCH v1] arm64: dts: rockchip: remove vdd_log from rk3399-puma

[Klaus Goger]

vdd_log has no consumer and therefore will not be set to a specific
voltage. Still the PWM output pin gets configured and thence the vdd_log
output voltage will changed from it's default. Depending on the idle
state of the PWM this will slightly over or undervoltage the logic supply
of the RK3399 and cause instability with GbE (undervoltage) and PCIe
(overvoltage). Since the default value set by a voltage divider is the
correct supply voltage and we don't need to change it during runtime we
remove the rail from the devicetree completely so the PWM pin will not
be configured.

Signed-off-by: Klaus Goger <klaus.goger-SN7IsUiht6C/RdPyistoZJqQE7yCjDx5@public.gmane.org>

---

 arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi
index 910628d18add..1fc5060d7027 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi
@@ -155,17 +155,6 @@
 		regulator-min-microvolt = <5000000>;
 		regulator-max-microvolt = <5000000>;
 	};
-
-	vdd_log: vdd-log {
-		compatible = "pwm-regulator";
-		pwms = <&pwm2 0 25000 0>;
-		regulator-name = "vdd_log";
-		regulator-min-microvolt = <800000>;
-		regulator-max-microvolt = <1400000>;
-		regulator-always-on;
-		regulator-boot-on;
-		status = "okay";
-	};
 };
 
 &cpu_b0 {
-- 
2.11.0

Re: [PATCH v1] arm64: dts: rockchip: remove vdd_log from rk3399-puma

[Heiko Stuebner]

Am Dienstag, 5. Dezember 2017, 08:11:58 CET schrieb Klaus Goger:
> vdd_log has no consumer and therefore will not be set to a specific
> voltage. Still the PWM output pin gets configured and thence the vdd_log
> output voltage will changed from it's default. Depending on the idle
> state of the PWM this will slightly over or undervoltage the logic supply
> of the RK3399 and cause instability with GbE (undervoltage) and PCIe
> (overvoltage). Since the default value set by a voltage divider is the
> correct supply voltage and we don't need to change it during runtime we
> remove the rail from the devicetree completely so the PWM pin will not
> be configured.
> 
> Signed-off-by: Klaus Goger <klaus.goger-SN7IsUiht6C/RdPyistoZJqQE7yCjDx5@public.gmane.org>

applied as fix for 4.15

Thanks
Heiko