Arch Linux

tomracing

Member

Registered: 2014-06-03

Posts: 8

[SOLVED] asus ux390 screen brightness +keyboard backlights

After installing Arch on my asus UX390 i5 I am having some trouble getting the screen brightness controls to work.
I've tried a few solutions that fly around on the internet but so far to no real results.

In summary this is the UX390 with i5-7200U using intel graphics. I've gone for KDE plasma with sddm in my install.
xf86-video-intel is not installed as per instructions that it often conflicts with kde, but with the i915 not sure if that matters.

[tom@RivaVirtus ~]$ uname -a
Linux RivaVirtus 4.12.4-1-ARCH #1 SMP PREEMPT Fri Jul 28 18:54:18 UTC 2017 x86_64 GNU/Linux

lspci -v

        00:02.0 VGA compatible controller: Intel Corporation Device 5916 (rev 02) (prog-if 00 [VGA controller])
        Subsystem: ASUSTeK Computer Inc. Device 15c0
        Flags: bus master, fast devsel, latency 0, IRQ 127
        Memory at ee000000 (64-bit, non-prefetchable) [size=16M]
        Memory at d0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at f000 [size=64]
        [virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
        Capabilities: <access denied>
        Kernel driver in use: i915
        Kernel modules: i915

So far I've tried setting kernel parameters acpi_backlight=vendor or video or native.
and adding a conf file to /usr/share/X11/xorg.conf.d/ with the code below makes sddm segfault and failed to boot into graphical environment.

Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"
EndSection

I can echo values to the brightness in /sys/class/backlight/intel_backlight/brightness so something works.
however I also don't have brightness change options in the system-settings->global-shortcuts->KDE daemon
xev output on fn+brightness keys (of both screen and keyboard) does give something related to brightness changes:

KeyRelease event, serial 40, synthetic NO, window 0x3800001,
    root 0xd5, subw 0x0, time 1013582, (-681,877), root:(661,906),
    state 0x0, keycode 233 (keysym 0x1008ff02, XF86MonBrightnessUp), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyPress event, serial 41, synthetic NO, window 0x3800001,
    root 0xd5, subw 0x0, time 1016280, (-681,877), root:(661,906),
    state 0x0, keycode 232 (keysym 0x1008ff03, XF86MonBrightnessDown), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 41, synthetic NO, window 0x3800001,
    root 0xd5, subw 0x0, time 1017680, (-681,877), root:(661,906),
    state 0x0, keycode 238 (keysym 0x1008ff05, XF86KbdBrightnessUp), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyPress event, serial 42, synthetic NO, window 0x3800001,
    root 0xd5, subw 0x0, time 1018454, (-681,877), root:(661,906),
    state 0x0, keycode 237 (keysym 0x1008ff06, XF86KbdBrightnessDown), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

Is there a working solution?
If further info is needed please ask away.

Last edited by tomracing (2017-08-10 20:27:19)

ralph_13

Member

Registered: 2015-02-06

Posts: 73

Re: [SOLVED] asus ux390 screen brightness +keyboard backlights

To clarify, echoing values to /sys/class/backlight/intel_backlight/brightness does change the brightness?

I suppose what you mean by give "something related to brightness changes" is the XF86MonBrightnessDown etc? Those are just what the fn brightness keys are called, they're not actually doing anything.

Never used kde so I can't really help much further, though you could try installing something like xfce4-power-manager (I've had both intel and amd/ati asus laptops and xfce4-power-manager had the hotkeys working right out of the box on all of them) on a new user and allowing it to handle the brightness keys to see if it's purely kde related.

Head_on_a_Stick

Member

From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: [SOLVED] asus ux390 screen brightness +keyboard backlights

Have we tried loading the asus_nb_wmi module?

Your posted Xorg configuration file forces xf86-video-intel as the driver and you do not have this package installed; at any rate the "Backlight" option was a workaround for an old bug that no longer applies, IIRC.

---

Are you infected with Wetiko?

tomracing

Member

Registered: 2014-06-03

Posts: 8

Re: [SOLVED] asus ux390 screen brightness +keyboard backlights

Sorted, Thank you guys for the input it did set me on the right track for the solution.
Checked that the modules are loaded and indeed the asus modules were loaded so that was all good.
Also the keyboard light are in /sys/class/leds/ as asus::kbbacklight and again I could echo a value to brightness just like the backlight and it did adjust the brightness on the laptop.

In the system settings I didn't have any power management settings which I did see when I was trying KDE-neon to see how plasma is.
So I figured it must be my new installation of plasma-desktop, turned out I didn't have powerdevil which also pulled down klibscreen.
Now all is good and I have both backlight and keyboard light controls.