Re: [Qemu-devel] [PATCH][RFC 0/14] implement power chip

[Peter Maydell]

On 20 March 2013 00:56, li guang <address@hidden> wrote:
> 在 2013-03-19二的 10:15 +0000，Peter Maydell写道：
>> The point is that how exactly power controllers connect
>> to devices, and which devices respond to reset/suspend/etc
>> is a property of the individual machine being modelled.
>> An x86 PC will be different from an ARM devboard which is
>> different again from the Exynos4 ARM SoC. So to allow this
>> flexibility, you have to let the machine model do the configuration,
>> which you do by having the model wire up the power controller
>> to the devices in the same way it's done on hardware.
>
> agree, originally, I  made all devices can realize the power
> state callbacks, e.g. if one can do suspend, then it will
> realize DeviceState::suspend, so if system go to suspend,
> this method will be called.
> do you want some explicit way to configure for machine's
> devices if they can support power state changes?

The devices should just implement appropriate signals/connections
if they have a means of talking to a power controller, and the
board model should wire them up. That's all.

>> >> Hardware does it with signals, so should we.
>> >
>> > can these signals be viewed as the calling of corresponding methods?
>>
>> In some ways, they are -- but the wiring up of the source of
>> the call to the implementation is done at runtime as devices
>> are connected together.
>
> So, can I go ahead to do this work?

Well, it's not for me to say what you should do, but you
still seem to be trying to do this with device methods,
which (as I've argued above) I think is the wrong approach.

-- PMM