Hello,

KDE 4.12.4 / Arch / 3.14.0 on a Lenovo Thinkpad T440s (very recent model).

Most control keys like volume are working prefectly with KDE.

Screen brightness control works too, I can use KDE energy management to control the brightness.

But KDE does not react to the button presses. When I try to reassign the buttons with khotkeys it jumps back to the default, indicating I try to customize the button to the default value.

xev says

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MappingNotify event, serial 44, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 8, count 248

RRNotify event, serial 45, synthetic NO, window 0x5a00001,
    subtype XRROutputPropertyChangeNotifyEvent
    output eDP1, property Backlight, timestamp 2664863, state NewValue

RRNotify event, serial 48, synthetic NO, window 0x5a00001,
    subtype XRROutputPropertyChangeNotifyEvent
    output eDP1, property Backlight, timestamp 2666421, state NewValue


after several key presses. The first keypress did not generate a Backlight message right away.

Any idea what could be wrong here?

Thx!

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KeyRelease event, serial 36, synthetic NO, window 0x4600001,
    root 0xac, subw 0x0, time 464964700, (288,211), root:(291,234),
    state 0x10, keycode 223 (keysym 0x1008ff19, XF86Mail), same_screen YES,
    XKeysymToKeycode returns keycode: 163
    XLookupString gives 0 bytes:
    XFilterEvent returns: False


The reason why that is not mappable is because it isn't a keypress as far as KDE is concerned - it is something quite different. The above is something like what you should have seen when you released the brightness increase/decrease key.

Responding to these different events will require special code within Powerdevil i'm afraid. Please file a feature request at bugs.kde.org in order to get this implemented.

Ok, interestingly khotkeys does accept them as buttons, I can even assign the brightness down button for example to any arbitrary action, just used it to show/hide Yakuake.
It also works the other way around, I can use e.g. F11 / F12 for brightness control and it works perfectly.

I just can't use the brightness buttons for brightness control.

Can you try to assign those shortcut keys to other actions within System Settings > Shortcuts & Gestures > Global Shortcuts and see if it works for that action (Volume Up/Down with KMix for instance)?

That's exactly what I have done:

interestingly khotkeys does accept them as buttons, I can even assign the brightness down button for example to any arbitrary action, just used it to show/hide Yakuake.

Or did I misunderstand you?

I didn't have exactly the same issue but experienced limitations with the brightness settings in KDE (not enough levels).

So I used the following article in Archlinux wiki.
I also configured the Power Daemon to ignore the presses on the light up/down, so that there are no conflicts.

I also had to add:

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acpi_osi=Linux acpi_backlight=legacy

to my bootloader's line.

BTW, I use intel HD 3000 GPU, you'll have to find out what works with you (add, remove options, etc.)

Sorry, I interpreted "khotkeys" as meaning Custom Shortcuts - which operates slightly differently in terms of how the shortcuts themselves are set.
If you used the Global Keyboard Shortcuts module, then I can't explain why it wouldn't work - does assigning another key to the Brightness Up/Down action allow you to change it using that other key?

bcooksley wrote:Sorry, I interpreted "khotkeys" as meaning Custom Shortcuts - which operates slightly differently in terms of how the shortcuts themselves are set.
If you used the Global Keyboard Shortcuts module, then I can't explain why it wouldn't work - does assigning another key to the Brightness Up/Down action allow you to change it using that other key?

I used the global shortcuts menu and yes, I just assigned brightness up/down to F2/F4 and it works.

acpi_osi=Linux acpi_backlight=legacy as kernel command line changed nothing.

Thanks!

Okay, that means the action itself is working fine - the problem lies in the shortcuts system. I'm mystified though, as you have previously mentioned that assigning the brightness up/down keys themselves to another action (namely, activating Yakuake) worked. When you did this, were you informed that there was a shortcut conflict?

Yes, I was warned about a conflict:

Der Kurzbefehl „Monitor Brightness Down“ steht in Konflikt mit dem folgenden globalen Kurzbefehl:
Kurzbefehl „Monitor Brightness Down“ in der Anwendung „KDE-Dienst“ für die Aktion „Bildschirmhelligkeit verringern“

German, but I think you get the point.

KDE is 4.13.0 now

Okay, after reassigning those keys back to their correct shortcuts - can you try running kdebugdialog and enabling all areas?
Then tail ~/.xsession-errors while trying to change the brightness. Is any output of relevance given?

Nothing. Not only nothing of relevance, but just plain nothing. Also nothing if I'm using the change volume keys or mute (which are working flawlessly)

Yes, I enabled all debug switches and I tailed .xsession-errors, which was open for writing (opening/closing Yakuake [using F12] produced some output)

Sorry....

Okay, that is unfortunate. My guess would be that this is a bug in Powerdevil - it will be ignoring the keypresses deliberately for some reason I suspect (it likely believes the hardware will handle the brightness change when it isn't). Please file a bug report, including the specifics (only fails with the brightness keys, which work with other shortcuts).

I think I forgot to mention something important (I thought I mentioned it, but haven't found it in this thread)

Brightness control using the keys works. You have to press multiple times or hold down in order to get an increment. KDE does not reflect the change, no OSD, no movement of the slider in powerdevil.

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% ll /sys/class/backlight
insgesamt 0
lrwxrwxrwx 1 root root 0 25. Apr 07:32 acpi_video0 -> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video0/
lrwxrwxrwx 1 root root 0 25. Apr 07:32 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/


Sorry for forgetting this fact.

Ah, this explains it in part. Please file a bug against Powerdevil - it should still be showing an indicator, as long as it is aware that the brightness level is changing.