[Intel-gfx] uncleared pch fifo underrun on pch transcoder

[Alexander Couzens]

Hi,

I'm facing from time to time a "blue" screen on my lenovo x230. It happens at least 
twice  a day and starting annoying me. The screen went black or shows a one color view.
The x230 is running coreboot with native graphics (no vgabios).

My machine is still running when this happens, so I've
ssh access. As a workaround I can suspend and resume to fix the screen for while.

Any idea how I can debug this further or fix this?

Best,
lynxis

Kernel ring buffer shows before going to suspend:
[drm:intel_set_pch_fifo_underrun_reporting [i915]] *ERROR* uncleared pch fifo underrun on pch transcoder A

kernel: Linux version 4.4.5-1-ARCH,
x.org: X.Org X Server 1.18.1
[    13.701] (II) Module intel: vendor="X.Org Foundation"
[    13.701]    compiled for 1.18.1, module version = 2.99.917
[    13.701]    Module class: X.Org Video Driver
[    13.701]    ABI class: X.Org Video Driver, version 20.0

lspci
-[0000:00]-+-00.0  Intel Corporation 2nd Generation Core Processor Family DRAM Controller [8086:0104]
           +-02.0  Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126]
           +-04.0  Intel Corporation Device [8086:0103]
           +-19.0  Intel Corporation 82579LM Gigabit Network Connection [8086:1502]
           +-1a.0  Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 [8086:1c2d]
[..]
--
Alexander Couzens

mail: lynxis at fe80.eu
jabber: lynxis at fe80.eu
mobile: +4915123277221
gpg: 390D CF78 8BF9 AA50 4F8F  F1E2 C29E 9DA6 A0DF 8604
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