Russell King wrote: > We have some folk who want a method to trigger emergency suspends when > batteries got low, or if you move the battery cover, etc. These are > events which require fast reactions from the system, and coding up some > additional interface to pass such events to userland, have some daemon > running to monitor for those events, and issue a PM event is completely > overkill and, actually, unreliable. > I'm not sure to understand why a daemon is needed. Could you explain ? >> Could you point out where it is handled ? > > It's both machine class and CPU specific. I couldn't point you at > anything specific, except to say that different machines and ARM CPUs > handle it differently. > > Some CPUs have "wait for interrupt" instructions, some don't. Some > need special cache handling around this instruction, some don't. Some > machines have a CPU capable of "wait for interrupt" but must not use it. > > It's all handled by the CPU abstraction, and the machine class abstraction. > > See arch_idle in include/asm-arm/arch-*/system.h as the starting point > for the "default" (== always used) idle implementations. > thanks for that. Francis
