[SOLVED] Upgrade to XOrg 1.15 broke KWin and DRI_PRIME

Question

I did another "pacman -Syu" this morning hoping for an uneventful update. However, after a reboot I found my KDE to be in a pretty much useless. Windows were black except for decorations (http://prifuk.cz/non_drupal/kwin_black.jpg) and DRI_PRIME=1 doesn't run 3D acceleration on my Radeon DIS anymore. At first I suspected a problem with mesa but the problem persisted even after a downgrade to 10.0.1 which worked fine for me. Another suspect on the list is X.Org but I cannot roll back to 1.14 because everything apparently depends on GLAMOR now and I do not have all necessary packages in pacman's cache anymore.
I switched KWin to use XRender instead of OpenGL which at least renders the screen correctly, OpenBox works fine too. I might be wrong about X.Org being the cause but I can't think of anything else. Does anybody have any idea how to debug this issue? I have an Intel HD3000 + Radeon 6400M, both were working fine before the last update.
http://prifuk.cz/non_drupal/Xorg.0.log
Last edited by MadCat_X (2014-01-15 21:15:46)

Answer 1

I noticed this as well, though not using kwin. I got DRI_PRIME back by manually
xrandr --setprovideroffloadsink 0x55 0x7d
where the numbers are the given by
xrandr --listproviders
(xrandr is not installed by default with Xorg, package name xorg-xrandr).
Reference: Prime - ArchWiki
I have not yet delved deeper into why it's no longer set automatically.
EDIT: I probably jumped the gun, I have none of your problems, I just noticed DRI_PRIME=1 wasn't enough to use the radeon card. I probably had to:
xrandr --setprovideroffloadsink 0x55 0x7d
before as well.
Last edited by obscurity (2014-01-14 14:04:59)