I've tried that but it doesn't work. I think a DSDT edit would work or something else which is unknown.
No, there is no DSDT patch which solves the problem but here is a list of things which have to be set appropriately for wakeup to work:
- The BIOS settings.
- A system definition which matches your hardware.
- A framebuffer which matches your system definition (you might need to patch it for your hardware).
Try to mimic the configuration of the Mac model you are faking as close as possible. If this doesn't help you are out of luck because of the way your BIOS works.