https://bugs.freedesktop.org/show_bug.cgi?id=63599
--- Comment #30 from Paul Wolneykien wolneykien@gmail.com --- (In reply to comment #13)
Try comparing the following registers between fglrx and radeon:
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You can use radeonreg (as root): ./radeonreg regmatch 0x98FC
Here is the console mode comparison (radeon installs the framebuffer console, though):
$ diff -u fglrx-console.data radeon-console.data --- fglrx-console.data 2013-12-21 01:38:37.952290647 +0400 +++ radeon-console.data 2013-12-21 01:42:45.844348784 +0400 @@ -1,23 +1,23 @@ 0x98FC 0x00000000 (0) -0x98F8 0x00000000 (0) +0x98F8 0x02010002 (33619970) 0x8950 0xfffcf001 (-200703) 0x98F4 0x00fe0001 (16646145) 0x3F88 0x00fe0001 (16646145) 0x9B7C 0x00000000 (0) -0x3F90 0xffff0000 (-65536) -0x9148 0xffff0000 (-65536) +0x3F90 0x00000000 (0) +0x9148 0x00000000 (0) 0x3F94 0x00000000 (0) 0x914C 0x00000000 (0) 0x8954 0x00000000 (0) 0x2004 0x00000210 (528) 0x2008 0x00fac688 (16434824) 0x2768 0x00007000 (28672) -0x8B24 0x00000000 (0) -0xA008 0x00030000 (196608) -0xA020 0x00158011 (1409041) +0x8B24 0x00ff0fff (16715775) +0xA008 0x00010000 (65536) +0xA020 0x00158009 (1409033) 0xA02C 0x0000001b (27) 0x9100 0x00000000 (0) -0x913C 0x01000000 (16777216) -0x960c 0x76543210 (1985229328) +0x913C 0x00000004 (4) +0x960c 0x54763210 (1417032208) 0x9610 0x0000ba98 (47768) -0x88C4 0x00000000 (0) +0x88C4 0x000000c1 (193)
See if changing any of them to what fglrx programs before starting X with tiling disabled.
I've set each register values from fglrx-console.data and call xinit. Lockup again, nothing changes.