Bug#1144857: linux-image-amd64: LVDS panel turns off/on every few seconds on VALLEYVIEW graphics

Package: linux-image-amd64
Version: 6.12.101-1
Severity: important
X-Debbugs-Cc: [email protected], [email protected]
User: [email protected]
Usertags: amd64

On boot, once the video driver loads, the screen starts to flicker. It turns off/on every 2-3 seconds. Does not matter if text console or X is started.
This is a regression. This video card worked in bullseye (kernel 5.10) and bookworm (kernel 6.1).

$ dmesg | grep 915
...
[    7.542124] i915 0000:00:02.0: [drm] Found VALLEYVIEW (device ID 0f31) display version 7.00 stepping N/A
[    7.546702] i915 0000:00:02.0: vgaarb: deactivate vga console
[    7.549582] i915 0000:00:02.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[    7.588070] i915 0000:00:02.0: [drm] *ERROR* Failed to write source OUI
[    7.671369] [drm] Initialized i915 1.6.0 for 0000:00:02.0 on minor 0
[    7.707615] fbcon: i915drmfb (fb0) is primary device
[    8.978567] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device

$ lspci -nn
00:00.0 Host bridge [0600]: Intel Corporation Atom Processor Z36xxx/Z37xxx Series SoC Transaction Register [8086:0f00] (rev 0e)
00:02.0 VGA compatible controller [0300]: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display [8086:0f31] (rev 0e)
00:13.0 SATA controller [0106]: Intel Corporation Atom Processor E3800 Series SATA AHCI Controller [8086:0f23] (rev 0e)
00:14.0 USB controller [0c03]: Intel Corporation Atom Processor Z36xxx/Z37xxx, Celeron N2000 Series USB xHCI [8086:0f35] (rev 0e)
00:1a.0 Encryption controller [1080]: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Trusted Execution Engine [8086:0f18] (rev 0e)
00:1b.0 Audio device [0403]: Intel Corporation Atom Processor Z36xxx/Z37xxx Series High Definition Audio Controller [8086:0f04] (rev 0e)
00:1c.0 PCI bridge [0604]: Intel Corporation Atom Processor E3800 Series PCI Express Root Port 1 [8086:0f48] (rev 0e)
00:1c.1 PCI bridge [0604]: Intel Corporation Atom Processor E3800 Series PCI Express Root Port 2 [8086:0f4a] (rev 0e)
00:1c.2 PCI bridge [0604]: Intel Corporation Atom Processor E3800 Series PCI Express Root Port 3 [8086:0f4c] (rev 0e)
00:1c.3 PCI bridge [0604]: Intel Corporation Atom Processor E3800 Series PCI Express Root Port 4 [8086:0f4e] (rev 0e)
00:1f.0 ISA bridge [0601]: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Power Control Unit [8086:0f1c] (rev 0e)
00:1f.3 SMBus [0c05]: Intel Corporation Atom Processor E3800/CE2700 Series SMBus Controller [8086:0f12] (rev 0e)
03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 0c)
04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 0c)


-- System Information:
Debian Release: 13.6
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.12.101+deb13-amd64 (SMP w/4 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages linux-image-amd64 depends on:
ii  linux-image-6.12.101+deb13-amd64  6.12.101-1

linux-image-amd64 recommends no packages.

linux-image-amd64 suggests no packages.

-- no debconf information