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

Package:
src:linux
Source:
src:linux
Submitter:
Bogdan Veringioiu
Date:
2026-08-22 13:19:01 UTC
Severity:
normal
Tags:
#1144857#5
Date:
2026-08-19 12:22:59 UTC
From:
To:
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)
#1144857#16
Date:
2026-08-19 18:58:03 UTC
From:
To:
Hello Bogdan,

Can you please test the most recent kernel from unstable (or testing)
and if that doesn't work, bisect over the kernels available on
https://snapshot.debian.org/package/linux/.

If you need a more detailed instruction, don't hesitate to ask.

Best regards
Uwe
#1144857#23
Date:
2026-08-20 11:24:46 UTC
From:
To:
Hello Uwe,

thank you for your feedback.

With your instructions I was able to boot a couple of kernels and I pinpointed the version that introduced the regression:

6.1.x bookworm OK
6.6.15-amd64 OK
6.8.12-amd64 OK
6.9.12-amd64 OK
6.10.12-amd64 OK
6.11.10-amd64 NOK <--- The problem starts here
6.12.101+deb13-amd64 NOK
7.1.3+deb13-amd64 NOK


Thank you
Bogdan
#1144857#28
Date:
2026-08-21 06:16:01 UTC
From:
To:
Some extra info:

the display is connected via LVDS, but it is detected as eDP. It is a small industrial panel, resolution 640x480:

$ xrandr --verbose
Screen 0: minimum 320 x 200, current 640 x 480, maximum 16384 x 16384
eDP-1 connected primary 640x480+0+0 (0x45) normal (normal left inverted right x axis y axis) 519mm x 324mm
	Identifier: 0x40
	Timestamp:  66191981
	Subpixel:   unknown
	Gamma:      1.0:1.0:1.0
	Brightness: 1.0
	Clones:
	CRTC:       0
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter:
	EDID:
		00ffffffffffff000d12117570030000
		1918010495000078e28042ac5130b425
		10505300000001010101010101010101
		010101010101470980a020e014101040
		340007442100001cbb0780a020e01410
		1040340007442100001c000000fd0038
		4c1e5311000a202020202020000000fc
		0047303635564e30312056320a20000a
	Colorspace: Default
		supported: Default, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, RGB_WIDE_FIXED, RGB_WIDE_FLOAT, BT601_YCC
	max bpc: 10
		range: (6, 10)
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
	scaling mode: Full aspect
		supported: Full, Full aspect
	link-status: Good
		supported: Good, Bad
	CTM: 	1.000000 0.000000 0.000000
		0.000000 1.000000 0.000000
		0.000000 0.000000 1.000000
	CONNECTOR_ID: 91
		supported: 91
	non-desktop: 0
		range: (0, 1)
  640x480 (0x45) 23.750MHz -HSync +VSync *current +preferred
        h: width   640 start  656 end  720 total  800 skew    0 clock  29.69KHz
        v: height  480 start  483 end  487 total  500           clock  59.38Hz
  640x480 (0x46) 19.790MHz -HSync +VSync
        h: width   640 start  656 end  720 total  800 skew    0 clock  24.74KHz
        v: height  480 start  483 end  487 total  500           clock  49.48Hz
  640x400 (0x47) 41.750MHz -HSync +VSync DoubleScan
        h: width   640 start  676 end  740 total  840 skew    0 clock  49.70KHz
        v: height  400 start  401 end  404 total  415           clock  59.88Hz
  640x400 (0x48) 35.500MHz +HSync -VSync DoubleScan
        h: width   640 start  664 end  680 total  720 skew    0 clock  49.31KHz
        v: height  400 start  401 end  404 total  411           clock  59.98Hz
  640x360 (0x49) 37.250MHz -HSync +VSync DoubleScan
        h: width   640 start  672 end  736 total  832 skew    0 clock  44.77KHz
        v: height  360 start  361 end  364 total  374           clock  59.86Hz
  640x360 (0x4a) 31.875MHz +HSync -VSync DoubleScan
        h: width   640 start  664 end  680 total  720 skew    0 clock  44.27KHz
        v: height  360 start  361 end  364 total  370           clock  59.83Hz
  640x360 (0x4b) 18.000MHz -HSync +VSync
        h: width   640 start  664 end  720 total  800 skew    0 clock  22.50KHz
        v: height  360 start  363 end  368 total  376           clock  59.84Hz
  640x360 (0x4c) 17.750MHz +HSync -VSync
        h: width   640 start  688 end  720 total  800 skew    0 clock  22.19KHz
        v: height  360 start  363 end  368 total  374           clock  59.32Hz
  512x384 (0x4d) 32.500MHz -HSync -VSync DoubleScan
        h: width   512 start  524 end  592 total  672 skew    0 clock  48.36KHz
        v: height  384 start  385 end  388 total  403           clock  60.00Hz
  512x288 (0x4e) 23.250MHz -HSync +VSync DoubleScan
        h: width   512 start  532 end  580 total  648 skew    0 clock  35.88KHz
        v: height  288 start  289 end  292 total  299           clock  60.00Hz
  512x288 (0x4f) 21.000MHz +HSync -VSync DoubleScan
        h: width   512 start  536 end  552 total  592 skew    0 clock  35.47KHz
        v: height  288 start  289 end  292 total  296           clock  59.92Hz
  480x270 (0x50) 20.375MHz -HSync +VSync DoubleScan
        h: width   480 start  496 end  544 total  608 skew    0 clock  33.51KHz
        v: height  270 start  271 end  274 total  281           clock  59.63Hz
  480x270 (0x51) 18.625MHz +HSync -VSync DoubleScan
        h: width   480 start  504 end  520 total  560 skew    0 clock  33.26KHz
        v: height  270 start  271 end  274 total  278           clock  59.82Hz
  400x300 (0x52) 20.000MHz +HSync +VSync DoubleScan
        h: width   400 start  420 end  484 total  528 skew    0 clock  37.88KHz
        v: height  300 start  300 end  302 total  314           clock  60.32Hz
  400x300 (0x53) 18.000MHz +HSync +VSync DoubleScan
        h: width   400 start  412 end  448 total  512 skew    0 clock  35.16KHz
        v: height  300 start  300 end  301 total  312           clock  56.34Hz
  432x243 (0x54) 16.250MHz -HSync +VSync DoubleScan
        h: width   432 start  444 end  484 total  536 skew    0 clock  30.32KHz
        v: height  243 start  244 end  247 total  253           clock  59.92Hz
  432x243 (0x55) 15.250MHz +HSync -VSync DoubleScan
        h: width   432 start  456 end  472 total  512 skew    0 clock  29.79KHz
        v: height  243 start  244 end  247 total  250           clock  59.57Hz
  320x240 (0x56) 12.587MHz -HSync -VSync DoubleScan
        h: width   320 start  328 end  376 total  400 skew    0 clock  31.47KHz
        v: height  240 start  245 end  246 total  262           clock  60.05Hz
  360x202 (0x57) 11.250MHz -HSync +VSync DoubleScan
        h: width   360 start  372 end  404 total  448 skew    0 clock  25.11KHz
        v: height  202 start  204 end  206 total  211           clock  59.51Hz
  360x202 (0x58) 10.875MHz +HSync -VSync DoubleScan
        h: width   360 start  384 end  400 total  440 skew    0 clock  24.72KHz
        v: height  202 start  204 end  206 total  209           clock  59.13Hz
  320x180 (0x59)  9.000MHz -HSync +VSync DoubleScan
        h: width   320 start  332 end  360 total  400 skew    0 clock  22.50KHz
        v: height  180 start  181 end  184 total  188           clock  59.84Hz
  320x180 (0x5a)  8.875MHz +HSync -VSync DoubleScan
        h: width   320 start  344 end  360 total  400 skew    0 clock  22.19KHz
        v: height  180 start  181 end  184 total  187           clock  59.32Hz
VGA-1 disconnected (normal left inverted right x axis y axis)
	Identifier: 0x41
	Timestamp:  66191981
	Subpixel:   unknown
	Clones:
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter:
	link-status: Good
		supported: Good, Bad
	CTM: 	1.000000 0.000000 0.000000
		0.000000 1.000000 0.000000
		0.000000 0.000000 1.000000
	CONNECTOR_ID: 76
		supported: 76
	non-desktop: 0
		range: (0, 1)
DP-1 disconnected (normal left inverted right x axis y axis)
	Identifier: 0x42
	Timestamp:  66191981
	Subpixel:   unknown
	Clones:
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter:
	Colorspace: Default
		supported: Default, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, RGB_WIDE_FIXED, RGB_WIDE_FLOAT, BT601_YCC
	max bpc: 10
		range: (6, 10)
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
	subconnector: Unknown
		supported: Unknown, VGA, DVI-D, HDMI, DP, Wireless, Native
	link-status: Good
		supported: Good, Bad
	CTM: 	1.000000 0.000000 0.000000
		0.000000 1.000000 0.000000
		0.000000 0.000000 1.000000
	CONNECTOR_ID: 79
		supported: 79
	non-desktop: 0
		range: (0, 1)
HDMI-1 disconnected (normal left inverted right x axis y axis)
	Identifier: 0x43
	Timestamp:  66191981
	Subpixel:   unknown
	Clones:
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter:
	content type: No Data
		supported: No Data, Graphics, Photo, Cinema, Game
	Colorspace: Default
		supported: Default, SMPTE_170M_YCC, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, DCI-P3_RGB_Theater
	aspect ratio: Automatic
		supported: Automatic, 4:3, 16:9
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
	link-status: Good
		supported: Good, Bad
	CTM: 	1.000000 0.000000 0.000000
		0.000000 1.000000 0.000000
		0.000000 0.000000 1.000000
	CONNECTOR_ID: 86
		supported: 86
	non-desktop: 0
		range: (0, 1)


Thank you

Bogdan