An annoying problem to say the least. I have a laptop (Dell Precision M4500) and roughly 50% of the time, I boot to a black screen. Otherwise, I boot to a normal login just fine. Running Freya 0.3.2
I suspect it's a race condition in startup scripts, causing Nouveau to fail when it attempts to bind to the VGA controller before it's ready.
The laptop has an onboard Quadro FX 880M
$ lspci -nnk | grep -A2 VGA 01:00.0 VGA compatible controller : NVIDIA Corporation GT216GLM [Quadro FX 880M] [10de:0a3c] (rev a2) Subsystem: Dell Device [1028:040c] Kernel driver in use: nouveau
I was curious though, because the HDD, and Wifi lights would blink as if the laptop was running, but none of the Ctrl+Alt+F2 shortcuts would work still... So one day out of desperation, I closed the laptop long enough for the computer to automatically go to sleep. Upon reopening the laptop, the driver initialized itself properly. I'm able to use this to work around the issue consistently, so I think it's a configuration issue somewhere.
I'm not sure where to really go from here, and that's why I'm posting on SA to look for the next steps in debugging this issue.
I'm not sure if this log is relevant.
$ grep nouveau /var/log/Xorg.0.log [ 5.302] (==) Matched nouveau as autoconfigured driver 1 [ 5.302] (==) Matched nouveau as autoconfigured driver 3 [ 5.303] (II) LoadModule: "nouveau" [ 5.303] (II) Loading /usr/lib/xorg/modules/drivers/nouveau_drv.so [ 5.304] (II) Module nouveau: vendor="X.Org Foundation" [ 5.305] (==) Matched nouveau as autoconfigured driver 1 [ 5.305] (==) Matched nouveau as autoconfigured driver 3 [ 5.305] (II) LoadModule: "nouveau" [ 5.305] (II) Loading /usr/lib/xorg/modules/drivers/nouveau_drv.so [ 5.305] (II) Module nouveau: vendor="X.Org Foundation" [ 5.305] (II) UnloadModule: "nouveau" [ 5.305] (II) Unloading nouveau [ 5.305] (II) Failed to load module "nouveau" (already loaded, 0) [ 5.307] (II) [drm] nouveau interface version: 1.1.2 [ 5.651] (II) NOUVEAU(0): [DRI2] DRI driver: nouveau [ 5.651] (II) NOUVEAU(0): [DRI2] VDPAU driver: nouveau [ 5.703] (II) AIGLX: Loaded and initialized nouveau
Link to the full log: https://gist.github.com/karlapsite/fadab04dccf1a7090a6c