Re: [RFC part3 PATCH 2/2] ARM64 / clocksource: Use arch_timer_acpi_init()

Hanjun Guo
2013-12-04T14:27:36Z

On 2013年12月04日 01:08, Mark Rutland wrote:
> On Tue, Dec 03, 2013 at 04:41:31PM +0000, Hanjun Guo wrote:
>> Use arch_timer_acpi_init() on ARM64 to initialise arch timer
>> in ACPI way when DT is not available.
>>
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>> ---
>> arch/arm64/kernel/time.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
>> index 29c39d5..fb009da 100644
>> --- a/arch/arm64/kernel/time.c
>> +++ b/arch/arm64/kernel/time.c
>> @@ -67,6 +67,10 @@ void __init time_init(void)
>>
>> clocksource_of_init();
>>
>> + /* if can't be initialised from DT, try ACPI way */
>> + if (!arch_timer_get_rate())
>> + arch_timer_acpi_init();
>> +
> As mentioned on the previous patch, I think for the timebeing we should
> rely on CNTFREQ.
>
> Additionally, if you need to do this we should have an analagous
> mechanism to clocksource_of_init() that performs this initialisation for
> ACPI, and here we can call a clocksource_*_init function that does the
> right thing.
>
> There's no need for this file to know anything about ACPI.

Oh, Amit already have some patches to introduce clocksource_acpi_init()
like clocksource_of_init() did, please refer to the link below.

http://marc.info/?l=linaro-acpi&m=138131929721943&w=2

is this the idea you mentioned in your comments?

Thanks
Hanjun