Re: [RFC] MMC: Proposals on reworking clock and power management

[Roger Quadros <roger.quadros@nokia.com>]

On 10/28/2010 11:51 PM, ext Ohad Ben-Cohen wrote:
> On Thu, Oct 28, 2010 at 6:40 PM, Kishore Kadiyala
> <kishorek.kadiyala@gmail.com>  wrote:
>> On Thu, Oct 28, 2010 at 9:43 PM, Nicolas Pitre<nico@fluxnic.net>  wrote:
>>> This is not clear that this is something that the core can effectively
>>> help with.  Opportunistic power saving at the host controller level is
>>> pretty much hardware dependent and may wildly vary in capabilities...
>>> and bugs.  So in this later case I think the driver for the host
>>> controller is the best place to just set up a timer and gate the clock
>>> after a certain period of inactivity for example.
>
> makes sense, thanks.

just to be sure, we're talking about controller clock and not card clock. right?

>
>> Agree,
>> So briefly, calling pm_runtime_put_sync using a activity based timer
>> in the host Controller
>> driver will gate the clock to the controller .
>
> Just make sure you call pm_suspend_ignore_children(), because you want
> to be able to gate that clock even when the card is still active

Let's be specific when we say clock. Which clock?

-- 
regards,
-roger