Automatically turn off blinking blue LED

[Exhaust]

I have this command I have to input manually to turn off the annoying blinking blue LED:

Code: Select all

echo none > /sys/class/leds/blue:status/trigger

I've tried various commands I found in 6 year old forum posts to automatically turn the blue LED off on startup because this command turns itself off every time the system is rebooted, but so far none of the strategies have worked, all I can do that works is manually input this command.

How do you automatically control this LED?

[L67GS]

How about a shell script at boot?

[mad_ady]

You could try adding the command in /etc/rc.local before the exit statement.

[L67GS]

/etc/rc.local didn't work on my C0 project.
.bashrc could be an option
viewtopic.php?f=112&t=40211

[Exhaust]

You could try adding the command in /etc/rc.local before the exit statement.

I believe this is exactly what I did, it did not work.

How about a shell script at boot?

How?

[Exhaust]

/etc/rc.local didn't work on my C0 project.
.bashrc could be an option
viewtopic.php?f=112&t=40211

I don't understand what this is.

[mctom]

You could try adding the command in /etc/rc.local before the exit statement.

I believe this is exactly what I did, it did not work.

If that file didn't exist before, that could mean rc.local is disabled.
https://www.linuxbabe.com/linux-server/ ... th-systemd

[L67GS]

/etc/rc.local didn't work on my C0 project.
.bashrc could be an option
viewtopic.php?f=112&t=40211

I don't understand what this is.

.bashrc should be in your home folder, it's executed at login. Open the file, and put your command in it then reboot.

[mad_ady]

Come on, guys, this discussion is turning out to be more complicated than it needs to.
Let's fix it the proper way (the systemd way)!

So - to run a command on system boot, you need to create and enable a service. The service executes a command, handles dependencies and logging (which you don't need in this particular case). It's more convoluted than past solutions, but it's the correct way to do it in a systemd environment!

To create a service file you need to create a text file in /etc/systemd/system, like this (as root!):

Code: Select all

# cat /etc/systemd/system/turn-off-blue-led.service
[Unit]
Description=Turn off blue led
After=syslog.target

[Service]
ExecStart=/bin/bash -c "/usr/bin/echo none > /sys/class/leds/blue\:status/trigger"
Type=oneshot

[Install]
WantedBy=multi-user.target

Next, you can run it manually, to verify that it works:

Code: Select all

service turn-off-blue-led start
service turn-off-blue-led status

If you're satisfied with it, you can enable it to run on system boot with:

Code: Select all

systemctl enable turn-off-blue-led

Let us know if you get stuck.

[mctom]

I'm starting to think we need a FAQ thread with tips like that.
@mad_ady guided me into the proper ways od systemd services eons ago and I'm still glad to this day.

[tobetter]

Let me add one thing to use a device tree overlay, but not tested yet.

Code: Select all

diff --git a/arch/arm64/boot/dts/amlogic/mesong12_odroid_common.dtsi b/arch/arm64/boot/dts/amlogic/mesong12_odroid_common.dtsi
index f0abf6b23e32..83bce7acd857 100644
--- a/arch/arm64/boot/dts/amlogic/mesong12_odroid_common.dtsi
+++ b/arch/arm64/boot/dts/amlogic/mesong12_odroid_common.dtsi
@@ -56,7 +56,7 @@
 
 	leds {
 		compatible = "gpio-leds";
-		blueled {
+		blueled: blueled {
 			label = "blue:heartbeat";
 			gpios = <&gpio_ao GPIOAO_11 GPIO_ACTIVE_HIGH>;
 			linux,default-trigger = "heartbeat";
diff --git a/arch/arm64/boot/dts/amlogic/overlays/odroidc4/Makefile b/arch/arm64/boot/dts/amlogic/overlays/odroidc4/Makefile
index b2a7acc0c557..31cb19fa290a 100644
--- a/arch/arm64/boot/dts/amlogic/overlays/odroidc4/Makefile
+++ b/arch/arm64/boot/dts/amlogic/overlays/odroidc4/Makefile
@@ -27,7 +27,8 @@ dtbo-$(CONFIG_ARCH_MESON64_ODROIDC4) += spi0.dtbo		\
 					pwm_b-backlight.dtbo	\
 					gpio-joystick0.dtbo	\
 					gpio-joystick1.dtbo	\
-					display_vu7c.dtbo
+					display_vu7c.dtbo	\
+					blueled_off.dtbo
 
 targets	+= $(dtbo-y)
 always	:= $(dtbo-y)
diff --git a/arch/arm64/boot/dts/amlogic/overlays/odroidc4/blueled_off.dts b/arch/arm64/boot/dts/amlogic/overlays/odroidc4/blueled_off.dts
new file mode 100644
index 000000000000..9e73f94595a1
--- /dev/null
+++ b/arch/arm64/boot/dts/amlogic/overlays/odroidc4/blueled_off.dts
@@ -0,0 +1,13 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+	fragmemt@0 {
+		target = <&blueled>;
+
+		__overlay__ {
+			linux,default-trigger = "on";
+			default-state = "off";
+		};
+	};
+};

[Exhaust]

Come on, guys, this discussion is turning out to be more complicated than it needs to.
Let's fix it the proper way (the systemd way)!

So - to run a command on system boot, you need to create and enable a service. The service executes a command, handles dependencies and logging (which you don't need in this particular case). It's more convoluted than past solutions, but it's the correct way to do it in a systemd environment!

To create a service file you need to create a text file in /etc/systemd/system, like this (as root!):

Code: Select all

# cat /etc/systemd/system/turn-off-blue-led.service
[Unit]
Description=Turn off blue led
After=syslog.target

[Service]
ExecStart=/bin/bash -c "/usr/bin/echo none > /sys/class/leds/blue\:status/trigger"
Type=oneshot

[Install]
WantedBy=multi-user.target

Next, you can run it manually, to verify that it works:

Code: Select all

service turn-off-blue-led start
service turn-off-blue-led status

If you're satisfied with it, you can enable it to run on system boot with:

Code: Select all

systemctl enable turn-off-blue-led

Let us know if you get stuck.

Thank you! This seems to have worked great. This really should be pinned as a FAQ, I bought this device knowing barely anything about Linux, there's no way I could ever figure this out on my own without help.

[oqei]

Posting here even though the thread is stale, because I think I have a simpler solution, I hope it's fine.

On debian-based systems you can achieve this with less manual configuration:
Install sysfsutils, and change /etc/sysfs.conf to:

Code: Select all

# Disable blue LED
class/leds/blue:heartbeat/trigger = none

You can also configure the red LED using this:

Code: Select all

# Disable Red LED
class/gpio/gpio = 503
class/gpio/gpio503/direction = out
class/gpio/gpio503/value = 0

[rooted]

Posting here even though the thread is stale, because I think I have a simpler solution, I hope it's fine.

On debian-based systems you can achieve this with less manual configuration:
Install sysfsutils, and change /etc/sysfs.conf to:

Code: Select all

# Disable blue LED
class/leds/bluebeat/trigger = none

You can also configure the red LED using this:

Code: Select all

# Disable Red LED
class/gpio/gpio = 503
class/gpio/gpio503/direction = out
class/gpio/gpio503/value = 0

This should be added to the wiki as I've never seen anyone mention a way to control the red LED.

[oqei]

Posting here even though the thread is stale, because I think I have a simpler solution, I hope it's fine.
...

This should be added to the wiki as I've never seen anyone mention a way to control the red LED.

That is actually where I got the info from: https://wiki.odroid.com/odroid-hc4/appl ... d-hc4_only
It apparently only works for the HC4 though.

[rooted]

Posting here even though the thread is stale, because I think I have a simpler solution, I hope it's fine.
...

This should be added to the wiki as I've never seen anyone mention a way to control the red LED.

That is actually where I got the info from: https://wiki.odroid.com/odroid-hc4/appl ... d-hc4_only
It apparently only works for the HC4 though.

I was right at least, it deserved a wiki entry

[oqei]

Amending this for completeness: On a mainline kernel (6.0.0), this needs to be changed slightly: the blue LED is blue:status (instead of heartbeat), while the red one can be set without resorting to the GPIO pins, it is available as red:power. The devices can be controlled as any other LED.