Arch Linux

Description:

since the upgrade of mesa ( 11.1.2-1 -> 11.2.0-1) I notice a weird graphic bug,

when the bug occurs ( I use plasma 5 ) what I see is a permanent white pixel on coordinates "0,0", the first pixel on the top-left corner of the screen,

but if I immediatly switch to a console ( ctrl-alt-f2 ) and then go back to the X session then it fixes the corruption, no permanent white pixel on coordinates "0,0",

the bug can occur randomly, I thought it was a problem with my LCD screen ( a defect or an "hot pixel" ), but it's not an hardware problem, it's a software problem and I think the culprit is mesa 11.2.0-1,

I have a radeon HD4650 pcie and I use the radeon driver, maybe the code in mesa 11.2.0-1 related to amd cards and openGL has a problem,

this bug seems similar to an old bug :

https://bugs.launchpad.net/ubuntu/+source/unity/+bug/944701

Additional info:
* package version(s) mesa 11.2.0-1
* config and/or log files etc.


Steps to reproduce:
- upgrade to 11.2.0-1
- sometimes a permanent single white pixel is displayed in the top-left corner of the screen during a X session ( plasma 5 or gnome for example ), it looks like an "hot pixel" but it's not the case, the LCD screen is ok, it's a software problem ( mesa, something related to openGL and amd cards)
- if you switch to a console ( ctrl alt f2 ) and go back to X session then the bug disapears, no white pixel on the top-left corner