intermittent display on kaby lake/i915 from kernel 4.19 onwards

Submitted by masterpatricko@gmail.com

Assigned to Intel GFX Bugs mailing list

Link to original bug (#109215)

Description

Kernels 4.19 onwards (most recent test with kernel-default-4.20.rc7-1.1.g4731528.x86_64) consistently exhibit the following on my laptop (Kaby Lake/Intel i7-8550U/UHD 620):

• After bootloader, system manufacturer image from UEFI is displayed again instead of splash screen
  

* After bootloader, display is intermittent (sometimes completely black, sometimes working), usually switching in bursts a few times a second, then stable for a few seconds
This occurs on console, SDDM, kwin_x11, kwin_wayland, but NOT with IceWM or TWM.
Switching from working TWM/IceWM to vt1 (or similar) doesn't work
Ratio of screen working to black is better on battery, worse on AC power
Underlying system is functional the entire time

Both of these issues are never observed under kernel 4.18 or previous, with no configuration changes.

No obvious errors in /var/log/messages or Xorg. Dmesg looks normal except (on >kernel 4.19) for one instance per boot of
[drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun

kernel-default-4.20.rc7-1.1.g4731528.x86_64 (not working)
> dmesg | grep -E 'intel|i915|drm'
[ 2.715201] intel_idle: MWAIT substates: 0x11142120
[ 2.715202] intel_idle: v0.4.1 model 0x8E
[ 2.715901] intel_idle: lapic_timer_reliable_states 0xffffffff
[ 2.742959] intel_pstate: Intel P-state driver initializing
[ 2.743643] intel_pstate: HWP enabled
[ 2.764581] intel_pmc_core: initialized
[ 4.636640] fb0: switching to inteldrmfb from EFI VGA
[ 4.636755] [drm] Replacing VGA console driver
[ 4.638002] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 4.638003] [drm] Driver supports precise vblank timestamp query.
[ 4.638755] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[ 4.639090] [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4)
[ 4.932886] [drm] Initialized i915 1.6.0 20180921 for 0000:00:02.0 on minor 0
[ 4.943550] fbcon: inteldrmfb (fb0) is primary device
[ 4.943553] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[ 5.768688] snd_hda_intel 0000:00:1f.3: enabling device (0000 -> 0002)
[ 5.902718] intel_rapl: Found RAPL domain package
[ 5.902720] intel_rapl: Found RAPL domain core
[ 5.902721] intel_rapl: Found RAPL domain uncore
[ 5.902722] intel_rapl: Found RAPL domain dram
[ 6.143342] snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
[ 11.070529] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun

kernel 4.18 (working) dmesg is similar except for version string and no underrun error:
[ 5.074997] [drm] Initialized i915 1.6.0 20180514 for 0000:00:02.0 on minor 0



System: Host: hobbes.site Kernel: 4.18.15-1-default x86_64 bits: 64 compiler: gcc v: 8.2.1 Desktop: KDE Plasma 5.14.4
tk: Qt 5.12.0 wm: kwin_x11 dm: SDDM Distro: openSUSE Tumbleweed 20181224
Graphics: Device-1: Intel UHD Graphics 620 vendor: CLEVO/KAPOK driver: i915 v: kernel bus ID: 00:02.0 chip ID: 8086:5917
Display: x11 server: X.Org 1.20.3 driver: modesetting unloaded: fbdev,vesa alternate: intel compositor: kwin_x11
resolution: 1920x1080~60Hz
OpenGL: renderer: Mesa DRI Intel UHD Graphics 620 (Kabylake GT2) v: 4.5 Mesa 18.3.1 compat-v: 3.0
direct render: Yes


previously discussed at https://bugzilla.opensuse.org/show_bug.cgi?id=1119621