Enable deepest suspend power state on S2I
summary
Goal is to make suspend-to-idle reach the same low power as suspend-to-RAM by adding a deepest C-state and using cluster idling with correct power-domain topology. Work runs on an eight‑core A55 Unisoc phone on mainline kernel plus vendor drivers and firmware; changes add a configurable idle-state property and require platform callbacks so non‑last CPUs prepare cluster/DDR shutdown. Tests show mixed results: some boards match RAM suspend when secondary cores are unplugged, but DDR never enters self-refresh yet — further per‑component debug needed.
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chapters (5)
- 0:00Start
- 11:56Plug cores when suspend
- 14:04DDR self refresh for S2R and S21
- 16:30Next to go • To find out which part of components or processors didn't enter into deep sleep
- 21:04Power consumption on below scenarios
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