Created attachment 142144 [details]
/sys/cxlass/drm/card0/error

Since upgrading to recent tip-of-unstreap-linux kernel (4.19.0-rc8-00154-g467e050e9760) chromium does not work: I see a blank screen, and many messages,

i965: Failed to submit batchbuffer: Input/output error

Relevant bits of dmesg are:
 i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=none:owns=io+mem
[    2.903710] [drm] Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled
 [drm] Finished loading DMC firmware i915/skl_dmc_ver1_27.bin (v1.27)
[    2.908599] [drm:gen8_de_irq_handler [i915]] *ERROR* Fault errors on pipe A: 0x00000080
[    2.908638] [drm:gen8_de_irq_handler [i915]] *ERROR* Fault errors on pipe A: 0x00000080
[    2.908671] [drm:gen8_de_irq_handler [i915]] *ERROR* Fault errors on pipe A: 0x00000080
[    2.916406] [drm] HuC: Loaded firmware i915/skl_huc_ver01_07_1398.bin (version 1.7)
[    2.926673] [drm] GuC: Loaded firmware i915/skl_guc_ver9_33.bin (version 9.33)
[    2.939269] i915 0000:00:02.0: GuC firmware version 9.33
[    2.939273] i915 0000:00:02.0: GuC submission enabled
[    2.939275] i915 0000:00:02.0: HuC enabled
[    2.942388] [drm] Initialized i915 1.6.0 20180719 for 0000:00:02.0 on minor 0
[    2.950309] ACPI: Video Device [GFX0] (multi-head: yes  rom: no  post: no)
[    2.964279] input: Dell WMI hotkeys as /devices/platform/PNP0C14:01/wmi_bus/wmi_bus-PNP0C14:01/9DBB5994-A997-11DA-B012-B622A1EF5492/input/input12
[    2.966781] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:00/input/input11
[    2.967928] [Firmware Bug]: ACPI(PEGP) defines _DOD but not _DOS
[    2.968024] ACPI: Video Device [PEGP] (multi-head: yes  rom: no  post: no)
[    2.968060] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:0a/LNXVIDEO:01/input/input13[    3.009908] fbcon: inteldrmfb (fb0) is primary device
[    5.146383] Console: switching to colour frame buffer device 160x54
[    5.253227] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[   14.005961] [drm] GPU HANG: ecode 9:0:0xfbffffff, in Xorg [3089], reason: hang on rcs0, action: reset
[   14.005963] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[   14.005964] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[   14.005964] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[   14.005965] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[   14.005961] [drm] GPU HANG: ecode 9:0:0xfbffffff, in Xorg [3089], reason: hang on rcs0, action: reset
[   14.005963] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[   14.005964] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[   14.005964] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[   14.005965] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[   14.005966] [drm] GPU crash dump saved to /sys/class/drm/card0/error
[   14.005975] i915 0000:00:02.0: Resetting rcs0 for hang on rcs0
[   15.983449] i915 0000:00:02.0: Resetting chip for hang on rcs0
[   15.983851] i915 0000:00:02.0: GPU recovery failed

[    2.939273] i915 0000:00:02.0: GuC submission enabled

The hang here is the guc failing to submit work. Please reopen if the problem occurs without setting unsafe parameters.