[PATCH 2/3] corenet: Support gpio power/reset for corenet

[Scott Wood]

On 09/15/2016 03:03 AM, Andy Fleming wrote:
> I agree that halt and power off mean and have always meant different
> things to the kernel. The problem is that most desktop systems,
> having halted, pass control to the BIOS which--usually--shuts off the
> power. Am I wrong about this? I've been using shutdown -h now to turn
> off my Linux systems for nearly 2 decades now, but I admit that I
> don't do it often, and I tend to stick with whatever works.

>From the shutdown man page:

     -h
           Equivalent to --poweroff, unless --halt is specified.

Again, let's talk in terms of the kernel API rather than quirky
userspace commands.

FWIW, I've always used "halt -p" and recall the system not powering off
on PCs when I use plain "halt", though it's been many years since I've
tried.

>>>    I don't see any other platforms doing this.  How do the nodes get probed
>>>    for them?
>>>
>>>
>>>    The answer is I don't know, but this is a common issue with adding
>>>    new devices to the device tree in embedded powerpc. The only other
>>>    platforms which have gpio-poweroff nodes in their trees are in
>>>    arch/arm, and none of those platforms call the probing
>>>    function of_platform_bus_probe. I suspect they either probe every
>>>    root node, or they somehow construct the match_id. As noted in the
>>>    above-referenced commit, putting the nodes under the gpio bus does
>>>    not cause them to get probed. This seemed like the best way under
>>>    the current corenet code.
>>
>> Well, let's figure out what it is that PPC should be doing to have
>> things work the way it does on ARM.
> 
> For all of the devices? Or just these two?

All of them.  If ARM isn't maintaining these annoying lists why should
we have to? :-P

-Scott