Lukas F. Hartmann authored May 15, 2018 and Adam Jackson committed May 16, 2018

Hi,

I upgraded Xwayland and the assorted libraries from git masters today,
and noticed that glamor wouldn't work anymore on i.MX6/etnaviv. The
error was:

No provider of glVertexAttribDivisor found.  Requires one of:
    Desktop OpenGL 3.3
    OpenGL ES 3.0
    GL extension "GL_ANGLE_instanced_arrays"
    GL extension "GL_ARB_instanced_arrays"
    GL extension "GL_EXT_instanced_arrays"
    GL extension "GL_NV_instanced_arrays"

The problem is that etnaviv offers GLSL 140 on GL 2.1 and glamor
rendering assumes that glVertexAttribDivisor() is always available on
GLSL>=130, which is not the case here. Forcing GLSL 120 makes glamor
work fine again on this platform. After chatting with ajax in
#xorg-devel, the following solution was proposed.

This is my first time of submitting a patch, so please excuse me and
advise if I'm doing it wrong ;)

Cheers
Lukas (mntmn)
Reviewed-by: Eric Anholt <eric@anholt.net>