Comment 3 for bug 1242478

I'm commenting here because I have a very similar problem (and have had said problem for some time), but which manifests in something of the opposite way:

After boot my script, as yours, does `echo OFF > /sys/kernel/debug/vgaswitcheroo/switch`. Several seconds later, I begin receiving
[ 50.069942] radeon 0000:01:00.0: couldn't schedule ib
[ 50.069951] [drm:radeon_cs_ib_chunk] *ERROR* Failed to schedule IB !
in the kernel log/dmesg 50-100 lines/sec

At this point xrandr reports outputs for both the discrete and the integrated video cards. So, for example, if I have no external devices plugged in I'll receive:

Screen 0: minimum 320 x 200, current 1366 x 768, maximum 32767 x 32767
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 309mm x 173mm
   1366x768 60.1*+ 40.1
   1360x768 59.8 60.0
   1024x768 60.0
   800x600 60.3 56.2
   640x480 59.9
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
LVDS-1-1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1366x768 60.1*+
   1280x720 59.9
   1152x768 59.8
   1024x768 59.9
   800x600 59.9
   848x480 59.7
   720x480 59.7
   640x480 59.4
HDMI-1-0 disconnected (normal left inverted right x axis y axis)
VGA-1-1 connected (normal left inverted right x axis y axis)
   1024x768 60.0
   800x600 60.3 56.2
   848x480 60.0
   640x480 59.9
  1366x768 (0x47) 69.3MHz
        h: width 1366 start 1404 end 1426 total 1436 skew 0 clock 48.3KHz
        v: height 768 start 771 end 777 total 803 clock 60.1Hz
  1024x768 (0xc2) 65.0MHz
        h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
        v: height 768 start 771 end 777 total 806 clock 60.0Hz
  800x600 (0xc3) 40.0MHz
        h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
        v: height 600 start 601 end 605 total 628 clock 60.3Hz
  800x600 (0xc4) 36.0MHz
        h: width 800 start 824 end 896 total 1024 skew 0 clock 35.2KHz
        v: height 600 start 601 end 603 total 625 clock 56.2Hz

Upon connecting or disconnecting an external monitor, putting the computer into standby gdm crashes and I get the following lines onscreen and in the kernel log:
[ 922.267146] [drm:atom_op_jump] *ERROR* atombios stuck in loop for more than 5secs aborting
[ 922.267188] [drm:atom_execute_table_locked] *ERROR* atombios stuck executing CEA6 (len 62, WS 0, PS 0) @ 0xCEC2
[ 927.268332] [drm:atom_op_jump] *ERROR* atombios stuck in loop for more than 5secs aborting
[ 927.268372] [drm:atom_execute_table_locked] *ERROR* atombios stuck executing CEA6 (len 62, WS 0, PS 0) @ 0xCEC2
[ 927.268410] [drm:atom_execute_table_locked] *ERROR* atombios stuck executing C558 (len 861, WS 0, PS 0) @ 0xC5B5
[ 932.269534] [drm:atom_op_jump] *ERROR* atombios stuck in loop for more than 5secs aborting
[ 932.269617] [drm:atom_execute_table_locked] *ERROR* atombios stuck executing CEA6 (len 62, WS 0, PS 0) @ 0xCEC2
[ 937.270719] [drm:atom_op_jump] *ERROR* atombios stuck in loop for more than 5secs aborting
[ 937.270768] [drm:atom_execute_table_locked] *ERROR* atombios stuck executing CEA6 (len 62, WS 0, PS 0) @ 0xCEC2
[ 942.271910] [drm:atom_op_jump] *ERROR* atombios stuck in loop for more than 5secs aborting
[ 942.271994] [drm:atom_execute_table_locked] *ERROR* atombios stuck executing CEA6 (len 62, WS 0, PS 0) @ 0xCEC2

Then gdm starts. At this point the IB scheduling errors stop and the xrandr outputs associated with the disabled video card no longer appear. The above also occurs if I log out of a gdm session.

After this point, subsequent device changes and session logouts occur normally until the computer is restarted.

I haven't been keeping track (I haven't had time to mess with this) of this rigorously, but while the IB scheduling errors only showed up in 13.10, the atom_execute_table_locked/op_jump errors have occurred since at least 12.04, I believe. I believe the extra displays part of the bug has occurred since at least 12.10, but possibly before. These are all reported together because they all occur in a very predictable sequence.