[PATCH v2 09/18] ARM: OMAP4+: PM: Restore CPU power state to ON with clockdomain force wakeup method

Kevin Hilman khilman at linaro.org
Wed Apr 3 16:54:41 EDT 2013


Santosh Shilimkar <santosh.shilimkar at ti.com> writes:

> While waking up CPU from off state using clock domain force wakeup, restore
> the CPU power state to ON state before putting CPU clock domain under
> hardware control. Otherwise CPU wakeup might fail. The change is recommended
> for all OMAP4+ devices though the PRCM weakness was observed on OMAP5
> devices first.

Sounds reasonable, but can you describe the "weakness" a little more?

IOW, what exactly happens if this is not done?  It sounds like the CPU
might immediately go back to retention, but how does that happen unless
it does a WFI?

Also, this sounds like a fix to me, and should probably be broken out
accordingly.

Kevin




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