Re: [PATCHv2 04/19] ARM: OMAP4: PM: save/restore all DPLL settings in OFF mode

[Kevin Hilman <khilman@xxxxxx>]

"Menon, Nishanth" <nm@xxxxxx> writes:

> On Thu, May 17, 2012 at 3:52 AM, Shilimkar, Santosh
> <santosh.shilimkar@xxxxxx> wrote:
>> On Thu, May 17, 2012 at 12:34 PM, Shilimkar, Santosh
>> <santosh.shilimkar@xxxxxx> wrote:
>>> On Thu, May 17, 2012 at 4:12 AM, Kevin Hilman <khilman@xxxxxx> wrote:
>>>> Tero Kristo <t-kristo@xxxxxx> writes:
>>>>
> [...]
>>>> - Rather than hooking into omap4_enter_lowpower(), should use
>>>>  the cluster PM enter/exit notifier chain.
>>>>
>>> This is again specific to device OFF only and not related to CPU
>>> cluster state as such. So I don't think notifiers should be used here.
>>>
>>> O.w even when we attempt just MPU OSWR C-state, all these functions will
>>> get called in notifier chain.
>>>
>> Just a thought, we can have a separate notifier chain for device OFF. It can
>> allow use to get rid of 'enable_off_mode" kind of flags and can be
>> used by many drivers too.
>
> Like the overall idea, but one minor dumb concern might be sequencing
> of notifiers
>  - OFF entry and restore needs things to be executed in a specific sequence.
> How do we plan to ensure the sequence is maintained in a notifier call
> chain? one
> possible option might be a "priority" based scheme?

Or just combine the events that need a specific sequence into single
notifier callback function.

Kevin


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