Bugzilla – Bug 1179905
Laptop screen flickers sporadically
Last modified: 2022-02-18 09:34:17 UTC
I just installed a Dell Latitude E5270 laptop and noticed that the builtin screen flickers sporadically¹ for a fraction of a second on both, text console and X.
It looks a bit like a lose monitor cable, but I can exclude a hardware problem, because it also happens when I don't even touch the device, but it does not happen under Windows 10 that came preinstalled on the device.
I discussed this with Stefan Dirsch and he suspected a bug in KMS.
Please let me know what other information you need for tracking this down.
¹ intervals vary between a few seconds and several minutes
Could you give hwinfo output?
If it's i915 driver, you can try some option to disable the power management stuff, e.g. passing i915.enable_dc=0 i915.enable_fbc=0 enable_ips=0
Thanks, Takashi for the quick response, and yes, it is i915.
# hwinfo --gfxcard
20: PCI 02.0: 0300 VGA compatible controller (VGA)
[Created at pci.386]
Unique ID: _Znp.sD6karQZ3z3
SysFS ID: /devices/pci0000:00/0000:00:02.0
SysFS BusID: 0000:00:02.0
Hardware Class: graphics card
Device Name: "Onboard IGD"
Model: "Intel Skylake GT2 [HD Graphics 520]"
Vendor: pci 0x8086 "Intel Corporation"
Device: pci 0x1916 "Skylake GT2 [HD Graphics 520]"
SubVendor: pci 0x1028 "Dell"
SubDevice: pci 0x06dd
Driver Modules: "i915"
Memory Range: 0xe0000000-0xe0ffffff (rw,non-prefetchable)
Memory Range: 0xd0000000-0xdfffffff (ro,non-prefetchable)
I/O Ports: 0xf000-0xf03f (rw)
Memory Range: 0x000c0000-0x000dffff (rw,non-prefetchable,disabled)
IRQ: 127 (147708 events)
I/O Ports: 0x3c0-0x3df (rw)
Module Alias: "pci:v00008086d00001916sv00001028sd000006DDbc03sc00i00"
Driver Info #0:
Driver Status: i915 is active
Driver Activation Cmd: "modprobe i915"
Config Status: cfg=new, avail=yes, need=no, active=unknown
Primary display adapter: #20
[ 3.892359] fb0: switching to inteldrmfb from VESA VGA
[ 3.963879] Console: switching to colour dummy device 80x25
[ 3.963913] i915 0000:00:02.0: vgaarb: deactivate vga console
[ 3.965694] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 3.965696] [drm] Driver supports precise vblank timestamp query.
[ 3.966430] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[ 3.967850] [drm] Finished loading DMC firmware i915/skl_dmc_ver1_27.bin (v1.27)
[ 3.979238] PM: Image not found (code -22)
[ 3.981707] [drm] Initialized i915 1.6.0 20190822 for 0000:00:02.0 on minor 0
[ 3.984428] ACPI: Video Device [GFX0] (multi-head: yes rom: no post: no)
[ 3.985626] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:00/input/input3
[ 3.993552] fbcon: i915drmfb (fb0) is primary device
[ 3.995507] Console: switching to colour frame buffer device 240x67
[ 4.015529] i915 0000:00:02.0: fb0: i915drmfb frame buffer device
I will try your suggested options (one after the other?) at my earliest convenience.
>I will try your suggested options (one after the other?) at my earliest convenience.
Good question. Takashi?
(In reply to Stefan Dirsch from comment #3)
> >I will try your suggested options (one after the other?) at my earliest convenience.
> Good question. Takashi?
It does not hurt to specify all of them all together. If it helps, one can "bisect".
Anyway, Leap 15.2 is not supported anymore and 15.3 could work better here. Reinhard, if it is still a problem, could you try the latest 15.3 kernel?