Turning off tablet display and backlight?

[optilumin0x1]

I am trying to use openwrt on an old atom x5 processor tablet. Everything run except backlight control. dmesg seems to indicate that i915 never run or maybe found vga controller and linux seems to deferred probing this tablet vga controller. Because of that, backlight control is never created and i am unable to blank tablet display to turn it off. On debian, i915 atleast show some activity in dmesg and i am able to blank the display using setterm program or blankconsole param on the kernel.

[frollic]

there are multiple threads about setterm, did you for instance read [SOLVED] Firmware i915 error on OpenWrt boot - #4 by JustAnotherEndUser ?

[JustAnotherEndUser]

There are more details and a screenshot in this post:

Run Setterm --blank force on boot

I tried something on a hunch and was able to figure out a solution for this. You have to > redirect the command to /dev/tty0 ( console ) example: setting to blank screen after 1 minute of inactivity /usr/bin/setterm --blank 1 > /dev/tty0 I tested adding this to startup to blank the screen on an x86_64 device after 1 minute of inactivity. It works. [image] FYI @ OP Asgard11926

[optilumin0x1]

I run setterm from remote terminal and it return with terminal does not support blank option.

root@OpenWrt:~# cat /proc/cmdline 
BOOT_IMAGE=/boot/vmlinuz root=PARTUUID=87f4496b-d83e-02b1-83ba-27d36e177202 rootwait console=tty1 console=ttyS0,115200n8 noinitrd
root@OpenWrt:~# setterm --blank 1 >> /dev/tty0
setterm: terminal xterm-256color does not support --blank
root@OpenWrt:~# setterm --blank 1 >> /dev/ttyS0
setterm: terminal xterm-256color does not support --blank

When running setterm on display console, it doesn’t return anything and display doesn’t get blanked out or turned off

root@OpenWrt:~# setterm --blank 1
root@OpenWrt:~# setterm --blank 1 >> /dev/tty1
root@OpenWrt:~# setterm --blank 1 >> /dev/ttyS0
root@OpenWrt:~# 

[optilumin0x1]

Solved. I use consoleblank of kernel params set to 60 and build custom image to include

kmod-backlight-pwm kmod-i2c-designware-pci kmod-i2c-designware-platform i915-firmware kmod-pmbus-core

with this included kmod, i915 were able to probe vga controller and control tablet display on or off.

setterm --blank force

above command also able to turn off display, if run on tablet display console.

[JustAnotherEndUser]

@optilumin0x1

I run setterm from remote terminal and it return with terminal does not support blank option.

Try it with one single “>” to redirect instead of two, redirect to /dev/tty0 (console), and also put the timeout period (in minutes) that you want before the screen turns off.
This is what works for me:
/usr/bin/setterm --blank 1 > /dev/tty0

Also, you can put it in your startup so it is set on every device boot:

**EDIT: Also, you indicated having an Intel 915 chipset, so you may also want to review to see if you have these packages installed:

[optilumin0x1]

i miss that… thanks for pointing it out. with startup script i don’t need to worry about upgrading openwrt