(In reply to Alex Deucher from comment #17)
> (In reply to intermediadc@hotmail.com from comment #16)
> > why im sure it is an xorg issue or one of xorg  component issue
> > (cafedead),because on Lubuntu 14.04.5 i had kernel 4.9 and no issue but xorg
> > was 1.6
> 
> X has nothing to do with the kernel ring tests.  Those happen long before X
> gets involved.  If the ring tests fail, all acceleration is disabled so you
> need to sort out the kernel issue before addressing X.

Hi Alex,
can you check this my post? can be a kms issue this and  cafedead too?

on my quad g5 i have the RadeonHD 7750 as first 16x pcie 

0000:0a:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI]
Cape Verde PRO [Radeon HD 7750/8740 / R7 250E]
0000:0a:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Cape
Verde/Pitcairn HDMI Audio [Radeon HD 7700/7800 Series]

and the open firmware nouveau as the 3rd pcie 
0001:06:00.0 VGA compatible controller: NVIDIA Corporation G70GL [Quadro FX
4500] (rev a1)

On my kernel 4.10.8 i dont have a nouveau module installed .
this is my kenrel append: 
nouveau.modeset=0 video=nouveaufb:off radeon.modeset=1 video=radeonfb:off
pci=realloc radeon.dpm=1 pci=realloc video=offb:ff radeon.dpm=1 nosplash 

lsmod show  drm_kms_helper 2 amdgpu,radeon 

i removed the /etc/X11/xorg.conf 

If i made an xorg -configure , 
xorg produce a nouveau configuration xorg.conf on busid 6:0:0 
starting X made a black screen with cursor blinking 
so 
i removed the xorg driver for nouveau 
xorg -configure 
and xorg produce a modesetting xorg.conf on busid 6:0:0 
starting X made a black screen without blinking cursor 

so 
i removed the /usr/bin/xorg/modules/driver/modesetting 
and xorg -configure dont find any screen and not made any xorg.conf.new

i made my xorg.conf 
with radeon busid 10:0:0 
i have a glitched graphic ... 

i removed glemour module on xorg i have radeon working but without
acceleration...