Bug 20781 - [855GM] garbled LVDS output with tiling on, using non-KMS
Summary: [855GM] garbled LVDS output with tiling on, using non-KMS
Status: RESOLVED DUPLICATE of bug 20289
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: 7.4 (2008.09)
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: Jesse Barnes
QA Contact: Xorg Project Team
Keywords: NEEDINFO
Depends on:
Reported: 2009-03-20 18:20 UTC by Kalev Lember
Modified: 2009-03-31 15:23 UTC (History)
2 users (show)

See Also:
i915 platform:
i915 features:

Screenshot of garbled desktop (659.15 KB, image/png)
2009-03-20 18:20 UTC, Kalev Lember
no flags Details
Xorg log (22.75 KB, text/plain)
2009-03-20 18:22 UTC, Kalev Lember
no flags Details

Description Kalev Lember 2009-03-20 18:20:33 UTC
Created attachment 24102 [details]
Screenshot of garbled desktop

For a while I've had screen corruption on LVDS when I didn't use KMS and had tiling on. I mostly used external VGA connector and had no corruption in there, so I didn't care very much about this issue. The corruption doesn't occur when I either turn off tiling or switch to KMS.

However, a recent fences patch by Jesse Barnes made the issue mostly go away, with corruption remaining only in a few places. Before this patch the screen was totally garbled, but now it's only garbled a little bit. Details can be seen in attached screenshot.

The patch that changed the situation was:

commit 636d252f3b1eac687f7b11952e949c383cb86ed4
Author: Jesse Barnes <jbarnes@nietzche.localdomain>
Date:   Thu Mar 19 13:25:29 2009 -0700

    Don't install fences if the kernel is managing them

I have i855GM, using latest xf86-video-intel git, mesa 7.3, libdrm 2.4.5 and 2.6.29-rc8 kernel.

From xorg log:

(II) intel(0): [DRI2] Setup complete
(**) intel(0): Framebuffer compression enabled
(**) intel(0): Tiling enabled
(==) intel(0): VideoRam: 131072 KB
(II) intel(0): Attempting memory allocation with tiled buffers.
(WW) intel(0): xf86AllocateGARTMemory: allocation of 1536 pages failed
        (Cannot allocate memory)
(WW) intel(0): Allocation error, framebuffer compression disabled
(WW) intel(0): xf86AllocateGARTMemory: allocation of 10 pages failed
        (Cannot allocate memory)
(II) intel(0): Tiled allocation successful.
Comment 1 Kalev Lember 2009-03-20 18:22:13 UTC
Created attachment 24103 [details]
Xorg log
Comment 2 Gordon Jin 2009-03-22 02:20:03 UTC
looks similar to bug#20289 and #20721.
Comment 3 Jesse Barnes 2009-03-30 17:50:44 UTC
Can you try the latest driver bits?  I recently pushed the final fixes.  Also there's a patch 20289 that might help.
Comment 4 Kalev Lember 2009-03-31 15:22:45 UTC
The patch in bug #20289 fixes it for me.
Comment 5 Kalev Lember 2009-03-31 15:23:39 UTC

*** This bug has been marked as a duplicate of bug 20289 ***

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