Hi David,

Am 01.07.2017 um 06:42 schrieb 刘炜:
> OWL_CPUx_ADDR is the physical address of CPUx wakeup function.
> OWL_CPUx_FLAG is a valid flag of OWL_CPUx_ADDR. 
> 
> After CPUxs are wakeuped by SEV instruction, they will check their own 
> OWL_CPUx_FLAG register. If the register vlaue is 0x55aa, CPUx will jump to 
> OWL_CPUx_ADDR to boot up, otherwize go to sleep by WFE.
> 
> So the pen release staff is not necessary, you can remove these code safely.

Thank you for the quick confirmation!

I have just tested a patch, and it appears to work.

Is owl_v7_invalidate_l1 necessary? mach-sunxi (that Arnd pointed to as
example) uses secondary_startup directly, without custom assembler code.

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm/mach-actions/headsmp.S

> BTW: CPU2/3 must exit the power gate state before wakeup, and CPU1 is always 
> power on and has no power gate control.

Yes, the S500 SPS was luckily documented in the manual. The power-gating
for CPU2/3 is already implemented:

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm/mach-actions/platsmp.c

For S900 however SPS is sadly not documented... If you know who at
Actions Semi could help there, please also take a look at:
https://github.com/96boards/documentation/issues/59

Best regards,

Andreas

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