x220/native graphics: after some time the display shows only a one color blur image.
|Status:||Response Needed||Start date:||03/12/2016|
After some time the display goes into a one color blur mode.
Everything but the display continues to work. Changing to another tty doesn't help.
[22770.401257] [drm:intel_set_pch_fifo_underrun_reporting [i915]] ERROR uncleared pch fifo underrun on pch transcoder A
#5 Updated by Alexander Couzens over 3 years ago
#7 Updated by Alexander Couzens over 3 years ago
don't think this is a problem
[ 9.232164] [drm:intel_dump_pipe_config] [CRTC:21][setup_hw_state] config ffff8800baa3b800 for pipe A
[ 14.948348] [drm:intel_dump_pipe_config] [CRTC:21][setup_hw_state] config ffff88007fca8000 for pipe A
brightness is broken?!
[ 9.218958] [drm:intel_panel_setup_backlight] Connector LVDS-1 backlight initialized, enabled, brightness 4437/1552 (nativegfx)
[ 14.936242] [drm:intel_panel_setup_backlight] Connector LVDS-1 backlight initialized, enabled, brightness 3000/3000 (vgabios
-they use a different port config:- before re-init by X. later they have the same.
[ 9.232180] [drm:intel_dump_pipe_config] port clock: 76000 (nativegfx)
[ 14.948377] [drm:intel_dump_pipe_config] port clock: 75000 (VGABIOS)
-and have a different port size- before re-init by X. later they have the same.
pipe src size: 640x480 (nativegfx)
pipe src size: 720x400 (VGABIOS)
only found on vgabios:
[ 14.922811] [drm:parse_general_definitions] crt_ddc_bus_pin: 2
#8 Updated by Patrick Rudolph over 3 years ago
I've played a little bit with FDI link training on Sandybridge and it looks like it's very similar to the i915 kernel module.
But I discovered that the i915 kernel module expects the GPU to be configured and it doesn't reset all registers to a known state.
I accidentally disabled FDI scrambling and the display output was random, even after the kernel started...