White screen flickering with kernel = 6.4.6

Brief summary of the problem:

NOTE: I've checked this bug, this looks like a known issue in the past, but it is a new issue.

This issue was raised with Mario Limonciello discussions on improving https://wiki.gentoo.org/wiki/HP_Elitebook_845_G10 at the time, where the amdgpu.sg_display=0 kernel option had to be added to stop the screen from going white and flickering. But the kernel version has been upgraded to 6.4.6, DE: GNOME 44.3.

Hardware description:

• CPU: AMD Ryzen 9 PRO 7940HS w/ Radeon 780M Graphics (16) @ 4.000GHz
• GPU: c3:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Phoenix1 [1002:15bf] (rev d3) (AMD ATI c3:00.0 Phoenix1)
• System Memory: 63579MiB (Two slots, Hynix DDR5, 32GiB x2 = 64GiB)
• Display(s): Built-in display (2560x1600, 16:10, 120 Hz) and Philips Consumer Electronics Company 34" (2560x1080, 21:9, 59.98 Hz)
• Type of Display Connection: HDMI

System information:

• Distro name and Version: Gentoo Linux x86_64
• Kernel version: Linux r9pro 6.4.6-gentoo-x86_64 #1 SMP PREEMPT_DYNAMIC Wed Jul 26 17:24:53 CST 2023 x86_64 AMD Ryzen 9 PRO 7940HS w/ Radeon 780M Graphics AuthenticAMD GNU/Linux
• Custom kernel: N/A
• AMD official driver version: N/A

How to reproduce the issue:

The issue reproduction method is as follows:

amdgpu.sg_display=0 is really necessary, If this kernel option is not set, the following scenarios will cause white screen flickering (DE: GNOME 44.3):
a. When the main screen is displayed normally, an external 2560x1080 (21:9) screen is connected through HDMI, which will trigger flickering
b. After connecting to a 4K HD screen, when the scale is switched from 100% to 200%, it will trigger flickering
c. When switching the resolution of the external screen, it will trigger flickering

After setting amdgpu.sg_display=0 option, the flickering problem cannot be reproduced.

Note, This computer has two memory slots. I inserted two memory sticks to cause this problem. My memory has passed the memory test and has two slots (two 8GiB memories were inserted at the factory, and I replaced them with two 32GiB memories, and I ran the memory test for a day).

When I unplugged one memory stick and kept only one memory stick, the problem disappeared. Everything is working now.

Attached files:

Screenshots/video files

2 memory sticks (Although the photo is white, but there is flickering):

1 memory stick (works):

Log files (for system lockups / game freezes / crashes)

• N/A