Comment 2 for bug 1048261

> If I set GRUB_GFXPAYLOAD_LINUX=text in /etc/default/grub,
> I get the text-only boot logo with correct screen resolution on
> startup and monitor doesn't power off in this case.

Given that you have a drm framebuffer listed in /proc/fb, this shouldn't happen. Could you boot this way and attach the /var/log/dmesg that results?

In the first dmesg log, I see the following:

[ 4.990494] [drm] nouveau 0000:01:00.0: Setting dpms mode 3 on vga encoder (output 0)
[ 4.990503] [drm] nouveau 0000:01:00.0: Setting dpms mode 3 on TV encoder (output 1)
[ 5.152352] [drm] nouveau 0000:01:00.0: allocated 1280x1024 fb: 0x48000, bo eecfc800

I'm not sure what dpms mode 3 is. Do you have both a vga display and a TV out connected to this machine?

Later, we see:

[ 51.160214] [drm] nouveau 0000:01:00.0: Setting dpms mode 3 on TV encoder (output 1)
[ 51.170591] [drm] nouveau 0000:01:00.0: Setting dpms mode 0 on vga encoder (output 0)
[ 51.170603] [drm] nouveau 0000:01:00.0: Output VGA-1 is running on CRTC 0 using output A
[ 51.172240] [drm] nouveau 0000:01:00.0: Setting dpms mode 3 on TV encoder (output 1)
[ 60.039444] init: plymouth-stop pre-start process (1240) terminated with status 1

This suggests that 'dpms mode 3' is off, and 'dpms mode 0' is on, and the monitor is being turned on only towards the end of boot (the plymouth-stop error message shows that plymouth has died before it can be stopped normally).