On Thu, Aug 3, 2023, at 08:37, Yinbo Zhu wrote: > + loongson,suspend-address: > + $ref: /schemas/types.yaml#/definitions/uint64 > + description: > + The "loongson,suspend-address" is a deep sleep state (Suspend To > + RAM) firmware entry address which was jumped from kernel and it's > + value was dependent on specific platform firmware code. In > + addition, the PM need according to it to indicate that current > + SoC whether support Suspend To RAM. > + I just commented on this in the driver patch, assuming this was an MMIO address, but I'm even more confused now, since we try hard to not rely on being able to just interface with firmware like this. If this is executable code, where does this actually reside? Is this some SRAM that needs to execute the suspend logic in order to shut down memory and cache controllers? Or is this a runtime firmware interface similar to how UEFI handles its runtime services to keep the implementation out of the kernel? Does the code work with both traditional suspend-to-ram and modern suspend-to-idle logic? Arnd