[PATCH 1/3] ARM: OMAP2+: 32k-counter: Use hwmod lookup to check presence of 32k timer

[Shilimkar, Santosh]

On Tue, Apr 10, 2012 at 2:59 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Tue, Apr 10, 2012 at 02:27:36PM +0530, Santosh Shilimkar wrote:
>> On Tuesday 10 April 2012 02:14 PM, Russell King - ARM Linux wrote:
>> > On Mon, Apr 09, 2012 at 03:18:22PM -0500, Jon Hunter wrote:
>> >> True, but we would always want to use the 32k timer if CONFIG_PM is
>> >> specified. So what I am saying is that if a device has a 32ksync timer
>> >> and CONFIG_PM is defined, we always want to use the 32ksync timer and a
>> >> gptimer should never be used.
>> >
>> > Why?  What if you want to have PM enabled, and you also want to use the
>> > kernels high resolution timers, or you want more accurate timing than
>> > the 30.5us tick interval of the 32k timer?
>>
>> You might have missed the earlier comments on the thread. High
>> resolution GP timer(sysclk) will stop in deeper power states and
>> hence it can't be used with PM enabled usecases.
>
> Which means folk should be given the choice at boot time between running
> with the deeper power states and having a higher resolution timing source,
> rather than denying them the higher resolution timing source when PM is
> enabled.

Good point. My point is such facilities is already part of the kernel and
there is no need to add a new one. The last proposal was allowing user to
choose gptimer as a clocksource and then you already have facility to
disable C-state now so, all should work in general

Regards
Santosh