Re: Blank screen on resume
I took a look at this with a system I knows suspends/resumes reliably with Linux. The first problem is that in nvidia_suspend(), the ACPI-presence sanity check fails because the string literal "ACPI" should be "acpi". With that fixed, the NVIDIA driver no longer refuses to suspend. Another problem I noticed is that the X server does not appear to VT-switch out automatically in the suspend path, I had to do this manually (prior to calling `acpiconf -s 3`).
With all of the above, the system enters S3, as it does without the NVIDIA driver loaded. However, it never returns to a state in which I can interact with it (with or without the NVIDIA driver present). I tried disabling SMP, disabling networking and interaction through a serial console, but none worked.
I gave up for now, but maybe the above is helpful to you.