Created attachment 116632 [details]
xorg.conf

hello,

not sure that I'm sending this to the right mesa component: if not,
apologies and please redirect me

Starting with 10.6.0-rc1, mesa-10.6.x somehow breaks glamor (or it's
the other way around).

If I boot X11 with glamor enabled (`Option "AccelMethod" "glamor"' in
xorg.conf) and mesa-10.6.x, I get a black screen background (despite
"xsetroot -bg violet -fg white -mod 16 16" in my .xinitrc). Moreover,
xterms and in general all other windows have a black background; no
visible cursor in the xterms, but if I play with window exposure (by
lowering/raising them), I can see parts of them with the expected
appearance (eg xterm: white bg and violet fg).

If I run xrefresh, everything disappears into the black background;
then, if I focus the windows by moving the mouse upon them, the
decorations of the WM emerge (the windows' background remains black,
though)

It seems to be only a matter of background/appearance, in general:
functionality of the different clients seems to be fine, as far as I
can say (eg the shells in the xterms do work fine etc).

Everything is restored to normality if I boot X11 with mesa-10.6.x and
glamor disabled in xorg.conf.

Also, absolutely no problem with glamor enabled and mesa-10.5.x

Here are my specs:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cedar [Radeon HD 5000/6000/7350/8350 Series]

kernel          4.0.5
mesa            10.6.0
libdrm          2.4.61
xorg-server     1.17.2
xf86-video-ati  7.5.0
glamor-egl      0.6.0
llvm            3.6.1

mesa built with:

     --enable-texture-float
     --enable-gles1
     --enable-gles2
     --disable-openvg
     --enable-xa
     --enable-gbm
     --enable-gallium-gbm
     --enable-r600-llvm-compiler
     --enable-glx-tls
     --with-egl-platforms="drm,x11,wayland"
     --with-gallium-drivers="nouveau,r300,r600,radeonsi,svga,swrast" 
     --with-dri-drivers='radeon,nouveau,swrast'


I have no idea which might be the problem.

I will be happy to provide any other information which might be
useful in this regard

thank you very much in advance for any help