Re: [PATCH 3/4] pm: Handle HID0_SLEEP in the TLF_NAPPING hack.

Paul Mackerras wrote:

Scott Wood writes:

quoted

The e300 core (and probably most other 6xx chips) can only come out of
sleep mode with an interrupt.  However, interrupts are logically disabled
by the power management layer.

On powerbooks it's typically a hard reset rather than an interrupt.
Is it possible to use a hard reset on e300-based systems?

The 8313 can do this (see the deep sleep portion of the 83xx PM patch 
that I posted), but others can't.  Even on the 8313, it's not always 
desireable to use deep sleep, due to limited wakeup sourcers, higher 
latency, etc.

Also, if you use an interrupt, presumably the cpu has to do something
to clear the interrupt condition.  What would that be?

The caller's MSR[EE] is cleared in power_save_6xx_restore, so the 
interrupt won't happen again until the PM code re-enables MSR[EE].

-Scott