Created attachment 77117 [details]
dmesg output, suspend logs, other detail
Computer: Dell Dimension 4100 circa 2001
Graphics card: NVIDIA MX420, P17, AGP 4x, circa 2002-2003
Distribution: Debian Wheezy with LXDE and nouveau graphics driver
Once the computer is suspended, the attached monitor should also enter its
low power state (signified by the blue power led turning orange). This happens
properly when suspending Windows XP but does not happen when suspending Debian
Wheezy. With Debian Wheezy, the monitor first goes blank but not completely
dark. After a few seconds, the monitor fades from mostly dark to completely
dark but the power led remains blue when it should change to amber.
The machine wakes properly from the S1 suspend state.
I am new to linux but I believe that this problem is related to the nouveau
driver. The monitor can be placed into its low power state with xset. Also,
if the pm-util 99video shell script is modified to xset the monitor to its
low power state when suspending, it will go into that state but will awake
once the nouveau kernel module does its suspend stuff. See attachment.
The Dimension 4100 enters the S1 state upon suspend, S3 is not supported.
This behavior is identical with both Windows XP and Debian Wheezy.
Current draw in the S1 state is .20A under Windows XP and .25A with Wheezy.
The current draw difference may not be related to the graphics card but it is
interesting nevertheless. I have looked for related bugs but can't find any.
I speculate, however, that this problem may be common but just overlooked. It
appears that most people are interested in major failures like kernel panics
and what not.
One other thing. The S1 suspend currents quoted above are 120VAC. So the DELL
Dimension draws ~24Watts when suspended from Windows XP and ~30Watts when suspended from Debian Wheezy.
You haven't provided an indication of what kernel was in use. However, based on the log output, it seems "old", definitely pre-3.7. Can you check if this still happens with the latest kernels? If so, please supply a full, unedited dmesg that includes a suspend resume sequence, booted with nouveau.debug=trace