Bug 36332

Summary: Missing rendering in Unity dash
Product: Mesa Reporter: Christopher James Halse Rogers <chalserogers>
Component: Drivers/Gallium/r300Assignee: Marek Olšák <maraeo>
Status: RESOLVED MOVED QA Contact:
Severity: normal    
Priority: medium CC: niklas.spamfilter, om26er
Version: git   
Hardware: Other   
OS: All   
i915 platform: i915 features:
Attachments: Xorg.0.log

Description Christopher James Halse Rogers 2011-04-17 18:07:52 UTC
Forwarded from https://bugs.launchpad.net/ubuntu/+source/unity/+bug/726033

When rendering the Unity dash icons are frequently missing from the rendering.
This video is a good demonstration of the problem: https://launchpadlibrarian.net/68813544/unity-bug.ogv

This works on r600g, nouveau, i915 and i965, so it looks like it's a bug somewhere in r300g.

The dash rendering uses FBOs and ARB shaders, with glscissor for clipping.
Comment 1 Jay Taoko 2011-04-17 18:10:21 UTC
Created attachment 45747 [details]
Comment 2 Jay Taoko 2011-04-17 18:11:05 UTC
Created attachment 45748 [details]
Comment 3 Jay Taoko 2011-04-17 18:11:41 UTC
Created attachment 45749 [details]
Comment 4 Christopher James Halse Rogers 2011-04-17 18:18:27 UTC
This occurs on both mesa master (as of 2011/04/18, shown in logs) and 7.10.2.
Comment 5 Jay Taoko 2011-04-17 18:24:09 UTC
The bug can be reproduced on ATI R300/400/500 GPUs. These GPUs are no longer
supported by fglrx so I couldn't verify if it was strictly a driver issue or if
there was some error in our program code. However, the problem cannot be
reproduced with a Radeon HD 4670 and the open source driver (or fglrx). Nor can
it be reproduced with Intel GPUs such as the GMA 950 and above.

The bug manifest itself in the Unity Dash. When an action is performed to show
more icons in the dash, the rendering does not happen. Elements of the Dash
only appear after the mouse moves over them, but this is the result of Unity
refreshing the rendering. Some elements of the dash also disappear. This make
me think that clipping could be involved. Unity makes extensive use of opengl
Comment 6 Pavel Rojtberg 2011-04-20 02:49:45 UTC
there is now a workaround in this commit:

// jaytaoko: This is a hack for what looks like a bug (#726033) in the radeon opensource driver
// on R300/400/500. Rather than passing a null region to glScissor, we give the clip area a 1 pixel width.
Comment 7 Marek Olšák 2011-05-06 07:13:43 UTC
Unity doesn't work here after upgrade from 10.10. It hangs after logging in.

Could you possibly make a simple OpenGL test case reproducing this bug? It shouldn't be hard.
Comment 8 Tomasz P. 2013-01-14 15:43:12 UTC
Is it still an issue with current kernel and mesa ?
Comment 9 GitLab Migration User 2019-09-18 18:50:19 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/mesa/mesa/issues/334.

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