Comment 7 for bug 305458

X backtrace:

Thread 1 (Thread 47563531181504 (LWP 6713)):
#0 0x00002b423f1e1190 in nanosleep () from /lib/libc.so.6
No symbol table info available.
#1 0x00002b423f2140f4 in usleep () from /lib/libc.so.6
No symbol table info available.
#2 0x00002b4241505a7b in RADEONPllErrataAfterData (info=0x7fd520) at ../../src/radeon_driver.c:759
 RADEONMMIO = (unsigned char *) 0x2b424173b000 <Address 0x2b424173b000 out of bounds>
#3 0x00002b42414fcea9 in RADEONWaitForIdleCP (pScrn=0x7fbf60) at ../../src/radeon_commonfuncs.c:148
 ret = -22
 info = (RADEONInfoPtr) 0x7fd520
 RADEONMMIO = <value optimized out>
 i = 0
 __FUNCTION__ = "RADEONWaitForIdleCP"
#4 0x00002b424220b149 in XAALeaveVT (index=0, flags=0) at ../../../../hw/xfree86/xaa/xaaInit.c:716
 pScreenPriv = (XAAScreenPtr) 0x8f6cd0
 infoRec = (XAAInfoRecPtr) 0x8f72f0
#5 0x000000000046574d in AbortDDX () at ../../../../hw/xfree86/common/xf86Init.c:1304
 i = 1
#6 0x000000000055ebe3 in AbortServer () at ../../os/log.c:408
No locals.
#7 0x000000000055f1b5 in FatalError (f=0x56ec80 "Caught signal %d. Server aborting\n") at ../../os/log.c:554
 args = {{gp_offset = 16, fp_offset = 48, overflow_arg_area = 0x7fff6caad330, reg_save_area = 0x7fff6caad270}}
 beenhere = 1
#8 0x000000000048757c in xf86SigHandler (signo=11) at ../../../../hw/xfree86/common/xf86Events.c:1484
No locals.
#9 <signal handler called>
No symbol table info available.
#10 0x00002b423f1c3070 in memcpy () from /lib/libc.so.6
No symbol table info available.
#11 0x00002b4240749ce9 in getDrawableInfo (dpy=<value optimized out>, screen=0, drawable=<value optimized out>, index=0xb564d4, stamp=0xb564e0, x=0xb564e4,
    y=0xb564e8, width=0xb564ec, height=0xb564f0, numClipRects=0xb564f4, ppClipRects=0xb564f8, backX=0xb56500, backY=0xb56504, numBackClipRects=0xb5650c,
    ppBackClipRects=0xb56510) at ../../../GL/glx/glxdri.c:746
 pClipRects = (drm_clip_rect_t *) 0x1
 pBackClipRects = <value optimized out>
 size = 8
#12 0x00002b4247082e22 in __driUtilUpdateDrawableInfo () from /usr/lib/dri/radeon_dri.so
No symbol table info available.
#13 0x00002b4247089b8d in radeonGetLock () from /usr/lib/dri/radeon_dri.so
No symbol table info available.
#14 0x00002b4247087a9a in radeonFlushCmdBuf () from /usr/lib/dri/radeon_dri.so
No symbol table info available.
#15 0x00002b4240727e3f in DoMakeCurrent (cl=0xeb4a50, drawId=<value optimized out>, readId=44040226, contextId=<value optimized out>, tag=1)
    at ../../../GL/glx/glxcmds.c:631
 client = (ClientPtr) 0xeb96a0
 pDraw = (DrawablePtr) 0xf35230
 pRead = (DrawablePtr) 0xf35230
 reply = {type = 0 '\0', unused = 0 '\0', sequenceNumber = 0, length = 0, contextTag = 0, pad2 = 0, pad3 = 0, pad4 = 0, pad5 = 0, pad6 = 0}
 drawPixmap = (__GLXpixmap *) 0x0
 readPixmap = (__GLXpixmap *) 0x0
 glxc = (__GLXcontext *) 0xbd2ed0
 prevglxc = dwarf2_read_address: Corrupted DWARF expression.
#0 0x00002b423f1e1190 in nanosleep () from /lib/libc.so.6
quit
The program is running. Quit anyway (and detach it)? (y or n) Detaching from program: /usr/bin/Xorg, process 6713

I'll try Option "DMAForXv" "off" now.