Bug 59687

Summary:	garbage on screen vga->graphics mode transition
Product:	DRI	Reporter:	Dave Airlie <airlied>
Component:	DRM/Intel	Assignee:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Status:	CLOSED NOTOURBUG	QA Contact:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity:	normal
Priority:	medium	CC:	joe.konno
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Dave Airlie 2013-01-22 01:07:31 UTC

https://www.youtube.com/watch?v=0EzzwP5aisY

I've seen this on a sandybridge machine booting 3.7 kernel from Fedora 18.

A previous 3.6.9 based kernel doesn't show it.

The VGA mode screen appears to get trampled before the graphics driver screen loads.

I think booting with quiet makes it more apparant.

Comment 1 Chris Wilson 2013-01-22 01:11:05 UTC

fbcon transition, so I feel safe by hiding amongst the team...

P.S. Ben says he saw it. Tag.

Comment 2 Daniel Vetter 2013-01-22 08:52:05 UTC

So we splatter the screen full with funny characters before setting up the kms screen ... that's new ;-) No idea what's going on here.

Comment 3 Joe Konno 2013-01-23 02:03:08 UTC

Wanted to add a nugget from some IRC discussion: currently scrutinizing Fedora patches around kernel v3.6.9 .

Comment 4 Joe Konno 2013-01-23 02:55:27 UTC

I'm having a hard time reproducing with Arch's 3.6.11 kernel. As in, haven't seen the visual corruption yet at the specified point.

Comment 5 Dave Airlie 2013-01-23 04:35:17 UTC

okay this is wierd I can make it happen with nomodeset quiet so I think i915 is off the hook!

Though this means its either a wierd BIOS thing, or a wierd race, since I haven't seen it reported on older hw or anything non-intel.

Comment 6 Chris Wilson 2013-02-15 14:47:11 UTC

Since then, Dave worked out that it was mishandling of the "intensity" bit in the VT emulation: https://patchwork.kernel.org/patch/2038031/

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