https://bugs.freedesktop.org/show_bug.cgi?id=56139
Priority: medium Bug ID: 56139 Assignee: dri-devel@lists.freedesktop.org Summary: [bisected] kernel 3.7.0-rc1 breaks 6950 (CAYMAN) Severity: major Classification: Unclassified OS: All Reporter: alexandre.f.demers@gmail.com Hardware: All Status: NEW Version: XOrg CVS Component: DRM/Radeon Product: DRI
Using ArchLinux 64, own built kernel (vanilla) with an HD 6950 (CAYMAN).
When testing kernel 3.7-rc1, the screen becomes unreadable. It's either completely black or in a flickering state making the display unusable. It is very similar to what was observed in bug 43655.
At the time of bug 43655, the problem had been fixed by http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=.... So it was working OK with kernel 3.6.
I've bisected between kernel 3.6 and 3.7-rc1 and the faulty identified commit is the following: 62444b7462a2b98bc78d68736c03a7c4e66ba7e2 is the first bad commit commit 62444b7462a2b98bc78d68736c03a7c4e66ba7e2 Author: Alex Deucher alexander.deucher@amd.com Date: Wed Aug 15 17:18:42 2012 -0400
drm/radeon: properly handle mc_stop/mc_resume on evergreen+ (v2)
- Stop the displays from accessing the FB - Block CPU access - Turn off MC client access
This should fix issues some users have seen, especially with UEFI, when changing the MC FB location that result in hangs or display corruption.
v2: fix crtc enabled check noticed by Luca Tettamanti
Signed-off-by: Alex Deucher alexander.deucher@amd.com
:040000 040000 3e0d33c9b4eda29ced814fe9a863efe63e53f14c 4932561607b160734ec1eade927a9fe18c9f3f1b M drivers