[gentoo-user] Re: Need some help with switching KDE setup from i915 to radeon graphics

[walt <w41ter@gmail.com>]

On Sat, 5 Mar 2016 00:10:23 +0100
Frank Steinmetzger <Warp_7@gmx.de> wrote:

> Hello Fellows,
> 
> My PC had been running on Intel graphics for 1½ years. Finally, I got
> myself an AMD R7 370 today and installed it (together with a second
> set of 16 Gigs of RAM ^^).
> 
> I could use some help getting it working properly. Here is what I did:
> yesterday I enabled VIDEO_CARDS=radeon in make.conf and rebuilt world
> with --changed-use. I also reconfigured the kernel to build the Intel
> driver as a module and to include the radeon module.
> 
> After installing the card, at first I only had a black screen and
> found out (thanks to #gentoo) that I needed a firmware blob. Once
> that was installed, I had a KMS-enabled VT on my AMD-connected
> monitor. Yay.
> 
> Now I'm stuck with a malfunctioning X (or more specifically, KDE, as
> it seems). I can run AwesomeWM just fine. But when I try to start
> KDE, I see the first of those fading-in progress icons and then the
> screen goes black.
> 
> I created a test account to have a clean setup of KDE. This starts KDE
> partially, only up to a desktop with an empty panel. There is no mouse
> cursor to move around and no reaction to shortcuts such as Alt+F2.
> 
> What else could I have missed in my migration from Intel to AMD?
> eselect opengl only shows the xorg-x11 option. I had to comment out a
> modeline which I set manually in xorg.conf.
> 
> See attached:
> - /etc/X11/xorg.conf.d/gfx.conf
> - /var/log/Xorg.0.log from running startx with .xinitrc containing
> startkde. You can see those three blocks of modelines at the end. At
> around or just before this point the screen goes dark.

Random things to try while waiting for better ideas to try:

startx -- -logverbose 10

In your .xinitrc try /etc/X11/Sessions/<kde-start-script> if kde
supplies such a script.

Have you tried using kdm instead of startx?  (Even thinking about that
raises my blood pressure :)

Are you using anything from kde-plasma? (Just running 'eix plasma'
makes my blood pressure even higher.  The number of permutations
involved makes me glad I use xfce4, which is already way too complex
for my taste.  How xfce4 behaves depends a lot on whether its
compositing feature is on or off.  Does kde allow you to tweak stuff
like that?  Of course it does, but not if Xorg dies before you can do
the tweaking.  (Reaching for blood-pressure pills now...)