Fedora 23 Xorg Glamor failure w R7750

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It is not supported in any way.
Bugs may be filed in the bugzilla at http://bugs.freedesktop.org/.
Select the "xorg" product for bugs you find in this release.
Before reporting bugs in pre-release versions please check the
latest version in the X.Org Foundation git repository.
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X.Org X Server 1.17.99.901 (1.18.0 RC 1)
Release Date: 2015-09-01
X Protocol Version 11, Revision 0
Build Operating System:  4.0.8-200.fc21.ppc64p7
Current Operating System: Linux localhost.attlocal.net 4.2.3 #12 SMP Sat Nov 7 10:54:33 PST 2015 ppc64
Kernel command line: console=ttyS0,115200 console=tty0 mem=3500M pci=realloc raid=noautodetect rootdelay=3 root=PARTUUID=2e3366ab-02
Build Date: 24 October 2015  11:55:55PM
Build ID: xorg-x11-server 1.18.0-0.5.20150907.fc23
Current version of pixman: 0.33.2
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Sat Nov  7 22:07:05 2015
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
Mesa warning: couldn't open libtxc_dxtn.so, software DXTn compression/decompression unavailable
(EE) glamor0: GL error: FBO incomplete: driver marked FBO as incomplete [-1]

XXX fail to create fbo.
(EE)
(EE) Backtrace:
(EE) unw_get_proc_info failed: unsupported operation or bad value [-8]
(EE)
(EE) Segmentation fault at address 0x18
(EE)
Fatal server error:
(EE) Caught signal 11 (Segmentation fault). Server aborting
(EE)
(EE)
Please consult the Fedora Project support
         at http://wiki.x.org
 for help.
(EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
(EE)
(II) AIGLX: Suspending AIGLX clients for VT switch
xinit: giving upinated with error (1). Closing log file.
xinit: unable to connect to X server: Connection refused
cinit: unexpected signal 2