Bug 497599

Summary:	Screen brightness going up and down.
Product:	[Plasma] plasmashell	Reporter:	kdebugs8
Component:	Power management & brightness	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED NOT A BUG
Severity:	major	CC:	jpetso, natalie_clarius, nate
Priority:	NOR
Version:	6.2.4
Target Milestone:	1.0
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description kdebugs8 2024-12-17 12:46:24 UTC

SUMMARY
Screen brightness keeps going up and down on screen.
Powerdevil needs to be restarted possibly multiple times to get the another screen to show up in brightness settings.

STEPS TO REPRODUCE
1. Login to user.
2. See brightness going up and down.
3. Click brightness and color settings and see that only one monitor is shown.
4. Put in a command: systemctl --user restart plasma-powerdevil.service and after multiple times it shows the other screen.

OBSERVED RESULT
Brightness flickering up and down.
No second monitor showing on the brightness and color settings.
 
EXPECTED RESULT
Brightness staying the same. No brightness flicker.
Second monitor showing on the brightness and color settings.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 6.6.65-1-MANJARO
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.8.0
Qt Version: 6.8.1

ADDITIONAL INFORMATION
Wayland

Comment 1 kdebugs8 2024-12-17 12:51:26 UTC

After restarting the system it flickers up and down.

More info.

Operating System: Manjaro Linux 
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.8.0
Qt Version: 6.8.1
Kernel Version: 6.6.65-1-MANJARO (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor
Memory: 15.5 GiB of RAM
Graphics Processor: AMD Radeon RX 6600
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: B550 AORUS PRO V2

Comment 2 Jakob Petsovits 2024-12-18 00:11:11 UTC

So you are using a setup with two monitors. Do they happen to be the same model? When you run `ddcutil detect`, does it list both monitors with different serial numbers?

Comment 3 kdebugs8 2024-12-18 17:45:42 UTC

I have two different monitors. One 55" 4k tv and 1050p 24" monitor. Running that command gives me this.

Invalid display
   I2C bus:  /dev/i2c-3
   DRM connector:           card1-DP-2
   EDID synopsis:
      Mfg id:               PHL - Philips Consumer Electronics Company
      Model:                Philips FTV
      Product code:         1219  (0x04c3)
      Serial number:        
      Binary serial number: 16843009 (0x01010101)
      Manufacture year:     2018,  Week: 9
   DDC communication failed. (getvcp of feature x10 returned Error_Info[EIO in ddc_write_read_with_retry, causes: EIO])

Display 1
   I2C bus:  /dev/i2c-5
   DRM connector:           card1-HDMI-A-1
   EDID synopsis:
      Mfg id:               SAM - Samsung Electric Company
      Model:                SyncMaster
      Product code:         772  (0x0304)
      Serial number:        HS2P802252
      Binary serial number: 1346712114 (0x50453232)
      Manufacture year:     2007,  Week: 33
   VCP version:         2.0

Invalid display
   I2C bus:  /dev/i2c-7
   DRM connector:           card1-DP-2
   EDID synopsis:
      Mfg id:               PHL - Philips Consumer Electronics Company
      Model:                Philips FTV
      Product code:         1219  (0x04c3)
      Serial number:        
      Binary serial number: 16843009 (0x01010101)
      Manufacture year:     2018,  Week: 9
   DDC communication failed. (getvcp of feature x10 returned Error_Info[DDCRC_RETRIES in ddc_write_read_with_retry, causes: EREMOTEIO(10)])

Comment 4 kdebugs8 2024-12-21 15:11:51 UTC

Seems that inputting grub kernel boot command amdgpu.backlight=0 fixed the brightness going up and down.
The brightness going up and down never showed in percentages with the brightness applet.

The other screen not showing in the brightness applet still exists though.

Should i make a bug report on AMD gitlab instead about the brightness going up and down?

Comment 5 kdebugs8 2024-12-23 07:43:33 UTC

Scratch that. The brightness still keeps going up and down.

Comment 6 kdebugs8 2024-12-27 00:40:01 UTC

POWERDEVIL_NO_DDCUTIL=1 line to /etc/environment seemed to do the trick with the monitor brightness going up and down, but lost the ability to set my Samsung monitors brightness when doing it.

Comment 7 kdebugs8 2025-01-08 07:10:43 UTC

Never mind. The tv was broken. Went to black screen recently. :( 
So no bug to report.