On 10/31/2012 03:41 AM, Joseph Lo wrote:

This adds a "powered-down" state for cpuidle. It's a power gating idle
mode. It supports the secondary CPUs (i.e., CPU1-CPU3) to go into
powered-down state independently. When any of the secondary CPUs go into
this state, it can be power gated alone. There is a limitation on CPU0.
The CPU0 can go into powered-down state only when all secondary CPU is
offline. After CPU0 is in powered-down state, the CPU rail can be turned
off.

All CPUs entering powered-down state is not working. The CPU0 enters this
state only when secondary CPU is offline. This can be coverd by CPUquiet
and cluster switching mechanism.

OK, this appears to work OK. I have applied it to Tegra's
for-3.8/cpuidle branch.

V4:
* rebased on next-20121031

Purely as an FYI, being based on top of Tegra's for-3.8/cpuidle or
for-next branches would have been even better, although in practice this
time around, there were no conflicts applying it there.