[PATCH v2] arm64: dts: rockchip: Turn all LEDs on at boot for Radxa boards

[FUKAUMI Naoki]

Hi Diederik, Dragan,

On 11/11/25 23:46, Dragan Simic wrote:
> Hello Diederik,
> 
> On Tuesday, November 11, 2025 14:07 CET, "Diederik de Haas" <diederik at cknow-tech.com> wrote:
>> On Tue Nov 11, 2025 at 6:41 AM CET, FUKAUMI Naoki wrote:
>>> Radxa's boards turn all LEDs on at boot(loader), but some boards don't
>>> have `default-state` property in Linux kernel tree but have it in
>>> U-Boot tree instead[1].
>>>
>>> This patch adds `default-state = "on"` for (almost) all LEDs (with a
>>> few exceptions which should be "off" such as RGB LEDs on E25 and LAN/
>>> WAN LEDs on E20C/E52C).
>>
>> I'm missing the *why* these changes would be an improvement.
>>
>> Personally, for both 'heartbeat' and 'netdev' triggers, I want them to
>> be off by default and once it gets a 'heartbeat' or a 'netdev' trigger,
>> THEN I want the LED to be on/blinking.
> 
> That's a good question for Naoki.  My own preference would also
> be to have the device's power LED turned on by U-Boot as quickly
> as possible after supplying power to the board or turning it on
> by pressing the power button.  I'm actually not a big fan of
> having all the LEDs shining for a couple of seconds or so, which
> may actually look like some error condition to me.
> 
> Having all that in mind, I may suggest that just the U-Boot's
> behavior is changed to turn the power LEDs on only.

I can't quite explain it, but...

- 1st (Power) LED

The 1st (power) LED turns on automatically/immediately without software 
intervention. (On some boards, this LED cannot be controlled by software 
at all.)

In DTS, this should be described using `default-state = "on"`. The use 
of the Linux-specific property `linux,default-trigger = "default-on"` is 
unsuitable for non-Linux environments.

- 2nd (Heartbeat) LED

The 2nd (heartbeat) LED can be controlled by software. It should be lit 
up as quickly as possible to indicate that the very first software 
(e.g., the bootloader) is running.

On Linux, usually this is used as `linux,default-trigger = "heartbeat"`. 
It indicates that kernel is running (regardless of the `default-state` 
setting), and its behavior can be modified in user space.

Best regards,

--
FUKAUMI Naoki
Radxa Computer (Shenzhen) Co., Ltd.