Bug#615598: I get this error accompanied by a black screen
 

I have DPMS set to on, the machine is always up and will
come out of DPMS with a mouse movement 90% of the time. The
other 10% of the time the screen remains black and in power save
mode. The only way out of it is to switch to a console (ALT-SHIFT-Fn)
and back to gdm (ALT-SHIFT-F7), but I didn't know that the first
couple of times the error happened. What is worse than the
syslog spam is the absolute terror of having what appears to
be an unresponsive system as I've had two machines die recently
because of graphics adapter failure and or BIOS / motherboard
failures. I have what could be termed PTSD from black screens,
so coming out of DPMS sleep should work 100% of the time,
EDID checksum be damned.

I've seen other reports about this error which contained
patch suggestions varying from not polling or probing every connector
to remembering the EDID data and not probing at all but I can't
recall where these were or which distribution, I know they were
on launchpad.

I am running wheezy/sid with Intel 945GME video controller
and an ACER P191W monitor. I believe the connection protocol is
TMDS-8 but not sure now because the output from DRM no longer
reports that information on a mode switch from console to X and
vice versa. Previously these messages appeared:

/var/log/kern.log.1.gz:Nov 6 13:08:23 asusb202 kernel: [717721.609526]
[drm] TMDS-8: set mode 1440x900 19
/var/log/kern.log.1.gz:Nov 7 14:26:04 asusb202 kernel: [717723.773204]
[drm] TMDS-8: set mode 1440x900 19
/var/log/kern.log.1.gz:Nov 7 14:26:04 asusb202 kernel: [717727.653623]
[drm] TMDS-8: set mode 2a
/var/log/kern.log.3.gz:Nov 3 08:58:48 asusb202 kernel: [538812.916458]
[drm] TMDS-8: set mode 1440x900 19
/var/log/kern.log.3.gz:Nov 4 11:26:48 asusb202 kernel: [538820.074848]
[drm] TMDS-8: set mode 1440x900 19
/var/log/kern.log.3.gz:Nov 4 11:26:58 asusb202 kernel: [538834.523321]
[drm] TMDS-8: set mode 29

Also note that these messages just started becoming a problem in the
last couple of months, and while I can't pinpoint the exact release
of the kernel I have been running 2.6.32 for at least the last year
I believe.

'get-edid | parse-edid' and 'xset q' for DPMS settings.
Keyboard Control:
auto repeat: on key click percent: 0 LED mask: 00000000
XKB indicators:
00: Caps Lock: off 01: Num Lock: off 02: Scroll Lock: off
03: Compose: off 04: Kana: off 05: Sleep: off
06: Suspend: off 07: Mute: off 08: Misc: off
09: Mail: off 10: Charging: off 11: Shift Lock: off
12: Group 2: off 13: Mouse Keys: off
auto repeat delay: 500 repeat rate: 30
auto repeating keys: 00ffffffdffffbbf
fadfffefffedffff
9fffffffffffffff
fff7ffffffffffff
bell percent: 50 bell pitch: 400 bell duration: 100
Pointer Control:
acceleration: 2/1 threshold: 10
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 600 cycle: 600
Colors:
default colormap: 0x20 BlackPixel: 0 WhitePixel: 16777215
Font Path:
unix/:7100,/usr/share/fonts/X11/misc,/usr/share/fonts/X11/100dpi/:unscaled,/usr/share/fonts/X11/75dpi/:unscaled,/usr/share/fonts/X11/Type1,/usr/share/fonts/X11/100dpi,/usr/share/fonts/X11/75dpi,/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType,built-ins
DPMS (Energy Star):
Standby: 1201 Suspend: 1801 Off: 2401
DPMS is Enabled
Monitor is On
parse-edid: parse-edid version 2.0.0
parse-edid: EDID checksum passed.

# EDID version 1 revision 3
Section "Monitor"
# Block type: 2:0 3:ff
# Block type: 2:0 3:fd
# Block type: 2:0 3:fc
Identifier "P191W"
VendorName "ACR"
ModelName "P191W"
# Block type: 2:0 3:ff
# Block type: 2:0 3:fd
HorizSync 30-82
VertRefresh 50-75
# Max dot clock (video bandwidth) 140 MHz
# Block type: 2:0 3:fc
# DPMS capabilities: Active off:yes Suspend:yes Standby:yes

Mode "1440x900" # vfreq 59.887Hz, hfreq 55.935kHz
DotClock 106.500000
HTimings 1440 1520 1672 1904
VTimings 900 903 909 934
Flags "+HSync" "-VSync"
EndMode
# Block type: 2:0 3:ff
# Block type: 2:0 3:fd
# Block type: 2:0 3:fc
EndSection