Bug 497823

Summary:	The brightness goes to max after waking the laptop from sleep.
Product:	[Plasma] plasmashell	Reporter:	kde-bugzilla.jcyjs
Component:	Brightness and Color widget	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	creideiki+kdebugs, natalie_clarius
Priority:	NOR
Version First Reported In:	6.2.4
Target Milestone:	1.0
Platform:	Fedora RPMs
OS:	Linux
URL:	https://gitlab.freedesktop.org/drm/amd/-/issues/3853
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description kde-bugzilla.jcyjs 2024-12-23 12:43:35 UTC

SUMMARY
The brightness goes to max after waking the laptop from sleep. The brightness slider doesn't work after that. 

STEPS TO REPRODUCE
1. Install Fedora KDE and upgrade. You should be on version 6.2.4
2. Put the system (in my case a laptop) to sleep. Wake it from sleep.
3. The brightness is maximum even though the slider is at its original value. It's, also, not working.

OBSERVED RESULT
Brightness is at 100% and the brightness slider doesn't work.

EXPECTED RESULT
Brightness should be at the previously set value and the brightness slider should work.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 41
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
Kernel Version: 6.12.5-200.fc41.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × AMD Ryzen 5 3450U with Radeon Vega Mobile Gfx
Memory: 5.7 GiB of RAM
Graphics Processor: AMD Radeon Vega 8 Graphics

ADDITIONAL INFORMATION

Comment 1 Karl-Johan Karlsson 2024-12-24 07:35:13 UTC

I'm seeing almost the same thing on my Thinkpad X395 running Gentoo. After waking from suspend-to-RAM, the screen is incredibly bright, and the brightness slider only has effect between 100% and 80%. When the slider is set to anything below 80%, the actual brightness stays the same as when the slider is at 80%.

Operating System: Gentoo Linux 2.17
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
Kernel Version: 6.12.6-gentoo-x86_64 (64-bit)
Graphics Platform: X11
Processors: 8 × AMD Ryzen 7 PRO 3700U w/ Radeon Vega Mobile Gfx
Memory: 13.5 GiB of RAM
Graphics Processor: AMD Radeon Vega 10 Graphics

Comment 2 Karl-Johan Karlsson 2024-12-24 11:24:51 UTC

It looks like this is actually a kernel problem.

I looked at my upgrade history, and noticed that Plasmashell hadn't been upgraded before I noticed the problem with the backlight, but KDE-Frameworks* had. I tried downgrading KDE-Frameworks from 6.9 to 6.7, and had the same problem. I then tried booting an older kernel, and didn't have the problem.

Kernel 6.12.6 refuses to set brightness below 80%, with either KDE-Frameworks 6.7 or 6.9.
Kernel 6.12.5 refuses to set brightness below 30%, with either KDE-Frameworks 6.7 or 6.9.
Kernel 6.12.4 works, with either KDE-Frameworks 6.7 or 6.9.

If I can manage to fit in a lot of compilation between Christmas stuff, I'll see if I can bisect the kernel to the exact problematic commit. In the mean time, could you check if booting an older kernel also fixes this for you?

* KDE-Frameworks is a Gentoo package category. I tried downgrading just Solid, but the packages all have hard dependencies on exactly the same version, so I had to downgrade everything simultaneously. The packages are:
$ equery list --format '$cpv:$slot' 'kde-frameworks/*' | grep -F :6 | sort
kde-frameworks/attica-6.9.0:6/6.9
kde-frameworks/baloo-6.9.0:6/6.9
kde-frameworks/breeze-icons-6.9.0:6/6.9
kde-frameworks/frameworkintegration-6.9.0:6/6.9
kde-frameworks/karchive-6.9.0:6/6.9
kde-frameworks/kauth-6.9.0:6/6.9
kde-frameworks/kbookmarks-6.9.0:6/6.9
kde-frameworks/kcalendarcore-6.9.0:6/6.9
kde-frameworks/kcmutils-6.9.0:6/6.9
kde-frameworks/kcodecs-6.9.0:6/6.9
kde-frameworks/kcolorscheme-6.9.0:6/6.9
kde-frameworks/kcompletion-6.9.0:6/6.9
kde-frameworks/kconfig-6.9.0:6/6.9
kde-frameworks/kconfigwidgets-6.9.0:6/6.9
kde-frameworks/kcontacts-6.9.0:6/6.9
kde-frameworks/kcoreaddons-6.9.0:6/6.9
kde-frameworks/kcrash-6.9.0:6/6.9
kde-frameworks/kdav-6.9.0:6/6.9
kde-frameworks/kdbusaddons-6.9.0:6/6.9
kde-frameworks/kdeclarative-6.9.0:6/6.9
kde-frameworks/kded-6.9.0:6/6.9
kde-frameworks/kdesu-6.9.0:6/6.9
kde-frameworks/kdnssd-6.9.0:6/6.9
kde-frameworks/kdoctools-6.9.0:6/6.9
kde-frameworks/kf-env-6:6
kde-frameworks/kfilemetadata-6.9.0:6/6.9
kde-frameworks/kglobalaccel-6.9.0:6/6.9
kde-frameworks/kguiaddons-6.9.0-r1:6/6.9
kde-frameworks/kholidays-6.9.0:6/6.9
kde-frameworks/ki18n-6.9.0:6/6.9
kde-frameworks/kiconthemes-6.9.0:6/6.9
kde-frameworks/kidletime-6.9.0:6/6.9
kde-frameworks/kimageformats-6.9.0:6/6.9
kde-frameworks/kio-6.9.0:6/6.9
kde-frameworks/kirigami-6.9.0:6/6.9
kde-frameworks/kitemmodels-6.9.0:6/6.9
kde-frameworks/kitemviews-6.9.0:6/6.9
kde-frameworks/kjobwidgets-6.9.0:6/6.9
kde-frameworks/knewstuff-6.9.0:6/6.9
kde-frameworks/knotifications-6.9.0:6/6.9
kde-frameworks/knotifyconfig-6.9.0:6/6.9
kde-frameworks/kpackage-6.9.0:6/6.9
kde-frameworks/kparts-6.9.0:6/6.9
kde-frameworks/kpeople-6.9.0:6/6.9
kde-frameworks/kpty-6.9.0:6/6.9
kde-frameworks/kquickcharts-6.9.0:6/6.9
kde-frameworks/krunner-6.9.0:6/6.9
kde-frameworks/kservice-6.9.0:6/6.9
kde-frameworks/kstatusnotifieritem-6.9.0:6/6.9
kde-frameworks/ksvg-6.9.0:6/6.9
kde-frameworks/ktexteditor-6.9.0:6/6.9
kde-frameworks/ktexttemplate-6.9.0:6/6.9
kde-frameworks/ktextwidgets-6.9.0:6/6.9
kde-frameworks/kunitconversion-6.9.0:6/6.9
kde-frameworks/kwallet-6.9.0:6/6.9
kde-frameworks/kwidgetsaddons-6.9.0:6/6.9
kde-frameworks/kwindowsystem-6.9.0:6/6.9
kde-frameworks/kxmlgui-6.9.0:6/6.9
kde-frameworks/oxygen-icons-6.1.0:6
kde-frameworks/prison-6.9.0:6/6.9
kde-frameworks/purpose-6.9.0:6/6.9
kde-frameworks/qqc2-desktop-style-6.9.0:6/6.9
kde-frameworks/solid-6.9.1:6/6.9
kde-frameworks/sonnet-6.9.0:6/6.9
kde-frameworks/syntax-highlighting-6.9.0:6/6.9
kde-frameworks/threadweaver-6.9.0:6/6.9

Comment 3 Karl-Johan Karlsson 2024-12-24 18:03:52 UTC

Bisected to this commit:

commit 99a02eab82515343d536796aa917dee50aec1551
Author: Alex Deucher <alexander.deucher@amd.com>
Date:   Mon Nov 25 13:59:09 2024 -0500

    drm/amdgpu: rework resume handling for display (v2)
    
    commit 73dae652dcac776296890da215ee7dec357a1032 upstream.
    
    Split resume into a 3rd step to handle displays when DCC is
    enabled on DCN 4.0.1.  Move display after the buffer funcs
    have been re-enabled so that the GPU will do the move and
    properly set the DCC metadata for DCN.
    
    v2: fix fence irq resume ordering
    
    Reviewed-by: Christian König <christian.koenig@amd.com>
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
    Cc: stable@vger.kernel.org # 6.11.x
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

Here's another report of similar behaviour with the same bisection: https://lists.freedesktop.org/archives/amd-gfx/2024-December/118209.html
And here's the issue in upstream's bug tracker: https://gitlab.freedesktop.org/drm/amd/-/issues/3853

Comment 4 kde-bugzilla.jcyjs 2024-12-26 13:45:51 UTC

(In reply to Karl-Johan Karlsson from comment #2)
> It looks like this is actually a kernel problem.

Yep, 100%. I tried it with a 6.11 kernel and the problem isn't there. It's a driver issue @ [amdgpu](https://gitlab.freedesktop.org/drm/amd/-/issues/3853)