Created attachment 122086 [details]
the source code of the program (.tar,xz)
Here's the source code of a simple program, that reproduces incorrect behavior
of PRIME. I actually wanted to try something different, but then I discovered
this bug. The program generates noise textures and displays them on a quad
using OpenGL 3.3. You can specify the size of the noise textures with the
program's first parameter.
The program runs fine on my Intel Ivy Bridge gpu and it also runs on my GeForce
GT 640M (Kepler) with nouveau and DRI_PRIME=1. When I increase the texture size
to 128 or something larger, the program's window sometimes (>= 50% chance)
becomes transparent (see attached screenshot) when using DRI_PRIME=1. This
*never* happens with texture sizes of 64 or less. If I remove the use of
textures completely from the program, it always runs fine as well. DRI_PRIME=1
glxgears always works as expected.
My system is Arch Linux with mesa 11.1.2-1 and kernel 4.4.1-2. I'm sorry that I
cannot install mesa-git since this is my computer for productive work.
Hopefully, someone else can reproduce the issue.
Steps to build the program:
- make sure you have SDL2 installed
- ./build.sh
- DRI_PRIME=1 ./a.out 512 <- might not work
- DRI_PRIME=1 ./a.out 64 <- always works for me