Thanks for reporting. You are partly right, since brightness keys are not handled for merely notifying the user of a brightness change but for changing the actual brightness instead. So it's more an action than a notification. What is missing is a way to monitor brightness changes when they happen outside of the power management framework realm, like in your case. Probably monitoring uevents is less expensive than watching for file changes, I'll give it a shot in the next days

Another point worth noting is that KOSD seems to work fine on eeepc

There are different kind of eeepc, some are using eeepc-laptop, others are using asus-wmi + eeepc-wmi, and I'm not sure they all have the same hotkey/brightness behavior.

I can confirm this. Pressing the brightness hotkeys on my Asus laptop does not elicit any events in KDE, although the screen brightness does get adjusted. This results in an actual brightness level different from the one stated by solid/KDE.

*** This bug has been confirmed by popular vote. ***

Dario, you've asked me to test a patch in bug 265357 comment 48. Sorry for nearly year delay, but please provide the patch, I'm happy to test and experienced with KDE and Qt development.

The thing is, we don't always want to show the OSD, for example we do not want to show the OSD when you are moding the brightness in the battery plasmoid (you already know how much brightness are you putting).

If we show the OSD when the brightness changes (does not matter from where we get the event) we can't do that since we can't know if we should show the OSD or not.

Not an easy thing to solve :/

I guess the obvious solution would be to allow plasmoid (and possibly others) to temporary disable the OSD ?

Not that easy, since each "key up" or "key down" will have different results in the system, will be difficult to know when the "key up" or the "plasmoid brightness modification" has been done.

Git commit 245493d67eed84f56b62bceae56aa83c58891f64 by Dario Freddi.
Committed on 20/04/2013 at 20:12.
Pushed by dafre into branch 'master'.

Merge branch 'brightness-changed-signals'

Now brightness changes are always detected and streamed when hardware changes.
The cache itself is hardware based.
Related: bug 313918

M  +46   -10   powerdevil/daemon/backends/upower/powerdevilupowerbackend.cpp

http://commits.kde.org/kde-workspace/245493d67eed84f56b62bceae56aa83c58891f64

Any chance the fix goes to 4.10 as well?

The fix is too big to be backported to 4.10 :/

I'm still seeing this problem. system76 lemur ultra. using brightness fn keys does change brightness but I get no OSD and KDE does not realize the brightness has changed. It works flawlessly in gnome, unity, XFCE... I have tried both kde 4.10, 4.11, and 4.11.1, same behavior in all.

same here on kde 4.11.1 with lenovo x220 and x230

same here means, the bug isn't fixed

Reopening based on recent comments.

Same here, using the keyboard hotkeys will change the brightness but no OSD.

On the other hand, changing the brightness from the "Battery Monitor" in the system tray is really annoying since when sliding the brightness control for every 10% change the OSD will come up and that will cause the Battery Monitor control dialog to disappear! (like if it lost focus) so I have to click on the battery icon again to continue adjusting the brightness. Same thing also happens when adjusting the brightness of the backlit keyboard from the battery monitor control dialog, however, when adjusting the keyboard brightness from hotkeys it works great and I do see the OSD too.

Fedora 19 x86_64
KDE 4.11.2
ASUS N550JV laptop (using module "asus_nb_wmi" and kernel parameter "acpi_osi= ")

on a ASUS X54C, i fix this by adding the flag acpi_osi= to Arch kernel line, and everything works fine :)

I still have the problem on my thinkpad x220 with KDE 4.12.1

Using Fn keys changes brightness but no OSD.

Hi,
For those who has no OSD while pressing the hotkey, I'm wondering is there a keyevent when hotkey pressed.
You can monitor the hotkey event by
   sudo showkey

Yes, there is. Keycode 224 and 225.

Same here. 224 and 225

Same for me, too. 224 and 225

Same issues on an Asus N550JK. Same keycodes.

Im now trying plasma 5 and here is works as expected.

Plasma 5 only ever shows the OSD when the user manually changes the brightness but never when the system automatically does.

(In reply to Kai Uwe Broulik from comment #26)
> Plasma 5 only ever shows the OSD when the user manually changes the
> brightness but never when the system automatically does.

Shouldn't it do the exact opposite?

No, when you change the brightness you want a feedback. When the system is changing it automatically you don't want to get annoyed by popups all the time.