Re: [linux-pm] [RFC][PATCH] Enable async suspend/resume of i2c devices

[Sonny Rao <sonnyrao-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>]

On Wed, Apr 6, 2011 at 10:22 PM, Rafael J. Wysocki <rjw-KKrjLPT3xs0@public.gmane.org> wrote:
> On Thursday, April 07, 2011, Sonny Rao wrote:
>> On Wed, Apr 6, 2011 at 3:31 PM, Mark Brown
>> <broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> wrote:
>> > On Wed, Apr 06, 2011 at 10:49:17AM -0400, Alan Stern wrote:
>> >
>> >> Neither is the case.  For these subsystems, the PM dependencies _are_
>> >> known.
>> >
>> > ...
>> >
>> >> Now, I have no idea what the situation is with regard to I2C...
>> >
>> > You definitely don't know *anything* about the relationships for I2C,
>> > especially in embedded systems.
>> >
>>
>> Would it be okay to enable this on a per-device basis where it is
>> known to be safe?
>
> Yes.

Ok, I'll probably submit a patch for the specific case of the slow
light sensor to the IIO
guys later on, and if I find cases where we get wins on other I2C
heavy platforms
(like ARM netbooks) I'll send those out as device-specific changes as well.

<snip>

> It is used by subsystems where dependencies between devices are known to
> generally follow the structure of the device hierarchy within the kernel
> (i.e. they are well-defined buses with well-defined parents and children).

Ok, thanks for the explanation!

Sonny