Using Etnaviv with mxsfb-drm

[Frieder Schrempf]

Hi Lucas, hi Marek,

while doing some tests on i.MX8MM with Etnaviv and mxsfb-drm (using the 
patches for DSIM, GPC, BLK-CTL, etc., see branch at [1]), I noticed that 
I don't seem to be able to run glmark2:

~# glmark2-es2-drm
=======================================================
     glmark2 2017.07
=======================================================
     OpenGL Information
     GL_VENDOR:     etnaviv
     GL_RENDERER:   Vivante GC600 rev 4653
     GL_VERSION:    OpenGL ES 2.0 Mesa 20.2.4
=======================================================
[build] use-vbo=false:Error: Failed to create FB: -22
Segmentation fault

Running a Qt application with the eglfs_kms backend produces a similar 
error, while running kmscube or applications without GPU rendering works 
fine.

What am I missing? When I used imx-drm, I didn't have any such issues. 
How is mxsfb-drm different?

Thanks in advance
Frieder

[1] https://github.com/fschrempf/linux/tree/v5.10-mx8mm-graphics