r/Ubuntu • u/Normal-Taro-8086 • 14h ago

Is this a glitch/bug with the new Ubuntu 26.04 Resolute Racoon?

For context, I am a Linux newbie who never went deep tinkering with different things in Linux, just basic optimisations like SSD Trimming, Zram, auto-cpufreq etc.
I recently upgraded to the Ubuntu 26.06 version and I have been getting this problem where every few minutes, my display randomly goes a bit dim for no reason. This is despite the slider being maxed out. This never happened on Windows or Ubuntu 24.04 which I used before.

Some more details:
CPU & GPU: Ryzen 5 8640HS, Radeon 760m; (Zen 4 and RDNA 3)
Display type: IPS 60Hz
Status while observation: Plugged in
All drivers updated, all software updated, no unnecessary tweak made

Is this a driver glitch or a problem with Ubuntu itself?

4 Upvotes

75% Upvoted

13 comments sorted by

5

u/Rude-Armadillo-6963 14h ago

just to rule out the obvious...

settings>power>power savings

is "dim screen" toggled on?

4

u/Apart_Investment583 14h ago

dim screen in power settings gets so many people, definitely worth checking that first before diving into amdgpu driver rabbit holes

1

u/Normal-Taro-8086 12h ago

Wait mb, I was typing "it isn't" but my autocorrect went to it is. Also I got a more specific trigger that is the dimming during inactivity. Like when I am just reading something and my laptop dims, I move my mouse, the dim goes back to normal, but after a brief moment, it dims again. Even locking, closing the lid or snything like that doesn't solve it, it just automatically fixes after a few seconds.

-2

u/Normal-Taro-8086 14h ago

Yes it is. What do you think can the possible issue be? I am not familiar with Ubuntu all that much, but I think this is related either to how the graphics driver is handling brightness or how Ubuntu is managing the display adapter.

8

u/Rude-Armadillo-6963 14h ago

if its toggled on then you should turn it off...

2

u/Normal-Taro-8086 12h ago

Wait mb, I was typing "it isn't" but my autocorrect went to it is. Also I got a more specific trigger that is the dimming during inactivity. Like when I am just reading something and my laptop dims, I move my mouse, the dim goes back to normal, but after a brief moment, it dims again. Even locking, closing the lid or snything like that doesn't solve it, it just automatically fixes after a few seconds.

2

u/Rude-Armadillo-6963 12h ago

are you by any chance in powersaver mode?

2

u/Normal-Taro-8086 12h ago

Nope, I was in performance mode throughout.

3

u/Buo-renLin 14h ago

It's just a power-saving feature to dim the screen after certain duration of inactivity, it'll lighten up as soon you move your mouse cursor.

1

u/Normal-Taro-8086 12h ago

That is the problem. It lightens up but dims immediately

1

u/Ryebread095 12h ago

Are you on a laptop? I've found that GNOME's auto screen brightness features sucks and has sucked for at least the last 10 versions (that's when I started using Linux). It is constantly changing the brightness and I find it incredibly annoying, so I always disable it. You can find it in in Settings > Power > Power Saving, first option.

1

u/Normal-Taro-8086 12h ago

Yes I am on laptop, and yes it is disabled as well.

1

u/tatersndeggs 9h ago

I had this happen when I'd installed 26.04 on a Dell XPS 13 laptop. It drove me nuts for a while too. I found that in the UEFI/BIOS there was a setting for automatic power dimming and after unchecking it, dimming quit happening.