Comment 19 for bug 257941

> Also, the output from xrandr and get-edid is identical, no matter how the monitor is connected.

Well, that's a good sign - implies that the detection is working the same regardless of whether the kvm is present or not. But we'll have to see once the current bug is resolved.

From the log file, I see it is parsing the edid into this (note the 'Unknown vendor field' warning):

(II) RADEON(0): EDID vendor "SAM", prod id 403
(II) RADEON(0): Output: LVDS, Detected Monitor Type: 2
(II) RADEON(0): EDID data from the display on output: LVDS ----------------------
(II) RADEON(0): Manufacturer: CPT Model: 13a6 Serial#: 0
(II) RADEON(0): Year: 2006 Week: 21
(II) RADEON(0): EDID Version: 1.3
(II) RADEON(0): Digital Display Input
(II) RADEON(0): Max Image Size [cm]: horiz.: 33 vert.: 21
(II) RADEON(0): Gamma: 2.20
(II) RADEON(0): No DPMS capabilities specified
(II) RADEON(0): Supported color encodings: RGB 4:4:4 YCrCb 4:4:4
(II) RADEON(0): First detailed timing is preferred mode
(II) RADEON(0): redX: 0.600 redY: 0.340 greenX: 0.309 greenY: 0.559
(II) RADEON(0): blueX: 0.149 blueY: 0.131 whiteX: 0.315 whiteY: 0.329
(II) RADEON(0): Manufacturer's mask: 0
(II) RADEON(0): Supported additional Video Mode:
(II) RADEON(0): clock: 68.9 MHz Image Size: 331 x 207 mm
(II) RADEON(0): h_active: 1280 h_sync: 1301 h_sync_end 1333 h_blank_end 1408 h_border: 0
(II) RADEON(0): v_active: 800 v_sync: 801 v_sync_end 804 v_blanking: 816 v_border: 0
(WW) RADEON(0): Unknown vendor-specific block f
(II) RADEON(0): FD1631154WB4
(II) RADEON(0): /BRZ����


(II) RADEON(0): EDID (in hex):
(II) RADEON(0): 00ffffffffffff000e14a61300000000
(II) RADEON(0): 15100103802115780a806d99574f8f26
(II) RADEON(0): 21505400000001010101010101010101
(II) RADEON(0): 010101010101ea1a0080502010301520
(II) RADEON(0): 13004bcf100000190000000f00000000
(II) RADEON(0): 0000000000206e050f00000000fe0046
(II) RADEON(0): 44313633313135345742340a000000fe
(II) RADEON(0): 002f42525a81c4eaff01010a2020004b
in RADEONProbeOutputModes
(II) RADEON(0): EDID vendor "CPT", prod id 5030
(II) RADEON(0): Output VGA-0 connected
(II) RADEON(0): Output LVDS connected
(II) RADEON(0): Using fuzzy aspect match for initial modes
(II) RADEON(0): Output VGA-0 using initial mode 1024x768
(II) RADEON(0): Output LVDS using initial mode 1024x768
after xf86InitialConfiguration
(**) RADEON(0): Display dimensions: (380, 300) mm
(**) RADEON(0): DPI set to (106, 135)

You could doublecheck that the same thing gets printed out when the KVM is attached - that will prove that the original KVM issue is resolved, which would be nice.

Meanwhile, as to what could be causing the black screen failure, with these kinds of issues the next step is usually to collect register dumps from both a) when it is working, and b) while it is failed with a black screen. In Jaunty we've updated the radeontool utility for this purpose. You can run it as follows:

  radeontool regmatch '*'

If you want to try using this on Intrepid, you can check out a copy of it from git here:
   http://cgit.freedesktop.org/~airlied/radeontool/