Kernel Bug Tracker – Bug 43231
black screen on sonyvaio vpccw1
Last modified: 2012-11-13 07:47:58 UTC
I though it was a nouveau problem but they told me it's from ACPI.
Also, on 3.3 backlight is reported as software , on 3.4 kernel thinks it is hardware and so nouveau does not enable control over it
so 3.3.4 works and 3.4 fails?
can you bisect which commit caused the failure?
I'm not able to do that, sorry.
This does appear to be a bug in drivers/acpi/video.c likely from commit ea9f8856bd6d4ed45885b06a338f7362cd6c60e5 as mentioned in other bug report. I was able to copy video.c from 3.3.6 branch and system booted no problem. Also I booted fine with "nomodeset" option and manually inserted nouveau, which produced these messages in kern.log: http://pastebin.com/3D3UZiw8
After further testing it seems my previous comment is unrelated to this bug.
i reverted the version of drivers/acpi/video.c before that commit and recompile the kernel and it works.
did you mean the second part of your comment?
yeah, after bisecting it appears to be a different regression in drm (43353).
dublicate of https://bugs.freedesktop.org/show_bug.cgi?id=50175.
in comments there the patch
that fixes it!
Copying files accross different kernel versions is a bad idea. Please consider reverting the commit in the future
Furthermore according to your dmesg you're experiencing another issue bug 43353
To the original reporter - the issue has been reported on freedesktop.org bug 5017 as well as kernel.org bug 43168, although it is an ACPI in nature
Consider closing the bug as a duplicate of bug 43168, as per original report
Patch in bug #43168 has been shipped in upstream linux kernel.
please reopen the bug report if the problem still exists.