https://bugs.freedesktop.org/show_bug.cgi?id=34534
--- Comment #8 from Alex Deucher agd5f@yahoo.com 2011-04-08 08:56:06 PDT --- Can you dump the following registers in both the working and non-working states using radeonreg or avivotool (http://cgit.freedesktop.org/~airlied/radeontool/)? You only need to dump the set that aligns to whichever crtc you are using for the problematic monitor (probably crtc 0 if you have just one monitor attached). 'xrandr --verbose' will tell you which crtc is in use.
crtc0: radeonreg regmatch 0x0bf0 radeonreg regmatch 0x0bf4 radeonreg regmatch 0x6b18 radeonreg regmatch 0x6b1c radeonreg regmatch 0x6b0c
crtc 1: radeonreg regmatch 0x0c00 radeonreg regmatch 0x0c04 radeonreg regmatch 0x7718 radeonreg regmatch 0x771c radeonreg regmatch 0x770c
crtc 2: radeonreg regmatch 0x0c10 radeonreg regmatch 0x0c14 radeonreg regmatch 0x10318 radeonreg regmatch 0x1031c radeonreg regmatch 0x1030c
crtc 3: radeonreg regmatch 0x0c20 radeonreg regmatch 0x0c24 radeonreg regmatch 0x10f18 radeonreg regmatch 0x10f1c radeonreg regmatch 0x10f0c
crtc 4: radeonreg regmatch 0x0c30 radeonreg regmatch 0x0c34 radeonreg regmatch 0x11b18 radeonreg regmatch 0x11b1c radeonreg regmatch 0x11b0c
crtc 5: radeonreg regmatch 0x0c40 radeonreg regmatch 0x0c44 radeonreg regmatch 0x12718 radeonreg regmatch 0x1271c radeonreg regmatch 0x1270c