Created attachment 144470 [details]
Screenshot of Minecraft exhibiting the bug

Please apologize my fuzzy description, but I have no plan how to explain it better. I've already posted this bug on launchpad (https://bugs.launchpad.net/bugs/1831688) but without any reaction.


On (K)Ubuntu 18.04 I get strange triangles in almost all (I guess in
all) apps using OpenGL.

glxinfo | grep 'string\|version' prints the following:

server glx vendor string: SGI
server glx version string: 1.4
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
GLX version: 1.4
    Max core profile version: 4.5
    Max compat profile version: 4.5
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: X.Org
OpenGL renderer string: AMD KAVERI (DRM 2.50.0, 5.0.0-16-generic, LLVM 8.0.0)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 19.2.0-devel (git-73dda85 2019-06-04 bionic-oibaf-ppa)
OpenGL core profile shading language version string: 4.50
OpenGL version string: 4.5 (Compatibility Profile) Mesa 19.2.0-devel (git-73dda85 2019-06-04 bionic-oibaf-ppa)
OpenGL shading language version string: 4.50
OpenGL ES profile version string: OpenGL ES 3.2 Mesa 19.2.0-devel (git-73dda85 2019-06-04 bionic-oibaf-ppa)
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

lshw -C display:

 *-display
       description: VGA compatible controller
       product: Kaveri [Radeon R5 Graphics]
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 1
       bus info: pci@0000:00:01.0
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
       configuration: driver=radeon latency=0
       resources: irq:43 memory:e0000000-efffffff memory:f0000000-f07fffff ioport:f000(size=256) memory:feb00000-feb3ffff memory:c0000-dffff

journalctl -p err -xb:

Jun 04 15:51:49 alischa kernel: ACPI BIOS Error (bug): Could not resolve [\_SB.PCI0.VGA.LCD._BCM.AFN7], AE_NOT_FOUND (20181213/psargs-330)
Jun 04 15:51:49 alischa kernel: ACPI Error: Method parse/execution failed \_SB.PCI0.VGA.LCD._BCM, AE_NOT_FOUND (20181213/psparse-531)
Jun 04 15:51:49 alischa kernel: ACPI Error: Evaluating _BCM failed (20181213/video-364)

Note on oibaf-ppa: the same happens also with the standard repository
packages and using this PPA was an attempt to fix the problem.

I can reproduce this bug in Minecraft (see attached screenshot),
Stellarium, and in Firefox with the page https://deck.gl/#/examples/core-layers/geojson-layer-paths

I tried all combinations of graphics drivers. fbdev finally used
software rendering (I think it was llvmpipe), which worked correct at
the expense of a very low frame rate.