OpenGL context crash/freeze on Intel UDH/UDH620/UHD630

[Pintea]

The issue has been described in detail here on the Graphics forum, but they sent me to this forum.

Basically the driver crashes when drawing any two VBOs with some two shaders. Isolated issue and posted code to reproduce it.

[andrewbt]

Following. Possible related issue here
https://community.intel.com/t5/Developing-Games-Graphics-on/Crash-in-Intel-HD-630-driver/td-p/1286438

[andrewbt]

In fact reading your description in original graphics thread in certain these issues are related. We are using instancing with multiple shaders and this crashes on Intel gpus.

[Pintea]

I wish you all the best. I have gotten no response until now, except to try it with a new driver every time a new one comes out.

Even though I posted a repro case with 100 lines of code or so, including shaders.

Anyway, it gets fixed by changing various (random) things in the shader. What I did was to replace:

float var = float(gl_VertexID % 2); // 0 or 1

with

if ((gl_VertexID % 2) == 0)
 var = 0;
else
 var = 1;

[andrewbt]

Thanks for the info, yes random things fixed it for us too. For example calling GL_Viewport in the wrong place = crash. I can hold out hope Intel will take a look at these threads and publish a fix but so far doesn’t seem likely!

[Pintea]

Getting back to this: it seems it also has something to do with having a sRGB backbuffer. If I don't enable SRGB, a ton of similar freezes go away.