Report issue similar to or same as BUG 234132

[Greg Rivers]

On Wednesday, December 19, 2018 3:16:16 PM CST Jeremy wrote:
> I would like to report an issue similar to BUG 234132. I was running FreeBSD
> stable 12 build r341835. My install included xserver 1.20 and mesa 18.3.1,
> with the drm-kmod for FreeBSD 12 (based on Linux KPI 4.16), using Haswell
> HD 4600 integrated video. I am also using the Intel driver, not
> modesetting. I was using Plasma 5.12.7, KF5 5.52 and QT5 5.11. Everything
> in Plasma was working fine, all of the KDE apps ran correctly and I had no
> issues.
> 
> When I upgraded to KF5 5.53 and QT5 5.12, I ran into very similar issues to
> what was reported from BUG 234132. There were rendering and screen
> flickering issues. My KDE desktop was virtually unusable from those issues.
>
I had the same experience after this update too. It must be a bad interaction with Haswell graphics. I have:
vgapci0 at pci0:0:2:0:     class=0x030000 card=0x198f103c chip=0x0a168086 rev=0x0b hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Haswell-ULT Integrated Graphics Controller'
    class      = display
    subclass   = VGA

~/.local/share/sddm/xorg-session.log records:
OpenGL vendor string:                   Intel Open Source Technology Center
OpenGL renderer string:                 Mesa DRI Intel(R) Haswell Mobile 
OpenGL version string:                  4.5 (Core Profile) Mesa 18.1.9
OpenGL shading language version string: 4.50
Driver:                                 Intel
GPU class:                              Haswell
OpenGL version:                         4.5
GLSL version:                           4.50
Mesa version:                           18.1.9
X server version:                       1.18.4
Requires strict binding:                yes
GLSL shaders:                           yes
Texture NPOT support:                   yes
Virtual Machine:                        no

I'm using sddm to start X/KDE. Apparently it's an initalization/start-up issue; if I disable compositing on startup[1] and then enable it after my KDE session is up and running, acceleration and compositing work fine thereafter. It's not perfect, but it's a serviceable work-around.


[1] System Settings/Display and Monitor/Compositor/Enable compositor on startup
    (This sets Enabled=false in the [Compositing] section of ~/.config/kwinrc)

-- 
Greg Rivers