[PATCH 2/2] ath79: add support for Dell SonicPoint ACi APL27-0B1

[tomek at terefe.re]

W dniu 2.02.2025 o 19:37, Sander Vanheule pisze:
> Hi Tomasz,

Hi

> 
> On Sun, 2025-02-02 at 16:10 +0100, Tomasz Maciej Nowak wrote:
>> +	reg_usb_vbus: regulator-usb-vbus {
>> +		compatible = "regulator-fixed";
>> +		regulator-name = "usb-vbus";
>> +		regulator-min-microvolt = <5000000>;
>> +		regulator-max-microvolt = <5000000>;
>> +		gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
>> +	};
>> +
>> +	output-usb-vbus {
>> +		compatible = "regulator-output";
>> +		vout-supply = <&reg_usb_vbus>;
>> +	};
>> +};
>>
>> +  DEVICE_PACKAGES += kmod-regulator-userspace-consumer
> 
> You could also add the regulator-boot-on to regulator-usb-vbus. If it is already enabled by the
> bootloader, regulator-boot-on will keep it enabled. Otherwise it should cause the regulator to be
> enabled (GPIO set low in this case) when the driver probes.

Issue is, bootloader doesn't enable power on the USB port, it's done when the
vendor modified EHCI driver was loaded, and while regulator-boot-on enables
power, the regulator is turned off later, as no driver seem to use it (a bug in
userspace-consumer driver?). I'll check if specifying hog property will allow to
still toggle it from userspace.

> You could also add regulator-always-on to regulator-usb-vbus, in which case the USB port can't be
> powered down anymore (from userspace). Is there any specific reason you would want to power the port
> down?

I can imagine someone using a LTE dongle to manage that AP, which sometime could
lock itself up and only power-cycle could restore it. Power-cycling the USB port
will restore the management capability without interrupting WiFi operation.

> Best,
> Sander

Regards

-- 
TMN