Re: [PATCH] arm64: dts: amlogic: odroid-n2: set usb-pwr-en regulator always on

From: Jerome Brunet
Date: Mon Feb 17 2020 - 02:39:03 EST



On Sun 16 Feb 2020 at 21:21, Anand Moon <linux.amoon@xxxxxxxxx> wrote:

> usb-pwr-en regulator is getting disable after booting, setting
> regulator-alway-on help enable the regulator after booting.

This explains what your patch does, not why it needs to be done.
Why does this regulator need be on at all time ? What device needs it
and cannot claim it properly ?

>
> [ 31.766097] USB_PWR_EN: disabling
>
> Fixes: c35f6dc5c377 (arm64: dts: meson: Add minimal support for Odroid-N2)
> Cc: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> Cc: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
> ---
> Patch generated on top of my earier patch.
> [0] https://patchwork.kernel.org/patch/11384531/
> [1] https://patchwork.kernel.org/patch/11384533/
>
> Before
> [root@alarm ~]# cat /sys/kernel/debug/regulator/regulator_summary | grep USB
> USB_PWR_EN 0 1 0 unknown 5000mV 0mA 5000mV 5000mV
> After
> [root@alarm ~]# cat /sys/kernel/debug/regulator/regulator_summary | grep USB
> USB_PWR_EN 1 1 0 unknown 5000mV 0mA 5000mV 5000mV
> ---
> arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> index 23eddff85fe5..938a9e15adfc 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> @@ -177,6 +177,7 @@ usb_pwr_en: regulator-usb_pwr_en {
> regulator-min-microvolt = <5000000>;
> regulator-max-microvolt = <5000000>;
> vin-supply = <&vcc_5v>;
> + regulator-always-on;
>
> /* Connected to the microUSB port power enable */
> gpio = <&gpio GPIOH_6 GPIO_ACTIVE_HIGH>;