I honestly don’t think the EDID is the problem.
On cold boot:
- All resolutions show up completely fine
- Changing the resolution, even to a non-standard one, does not produce the same black screen as when resuming from S3 sleep
- You can turn the display off and on (even repeatedly over and over again), and it behaves normally, and doesn’t show the black screen
I could be wrong, though…
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The ACPI tables do have some entries for things that the Linux kernel does not recognise, so there is a chance that one of those is the elusive reset that we’ve been looking for….