[PATCH v1 1/2] PM/devfreq: add suspend frequency support

[hl]

Hi MyungJoo Ham,

On 2016年11月02日 14:35, MyungJoo Ham wrote:
>> Add suspend frequency support and if needed set it to
>> the frequency obtained from the suspend opp (can be defined
>> using opp-v2 bindings and is optional).
>>
>> Change-Id: Iaa0d3848d63d9ce03f65ea76f263e4685a4c295e
>> Signed-off-by: Lin Huang <hl at rock-chips.com>
>> ---
>>   drivers/devfreq/devfreq.c | 17 ++++++++++++++++-
>>   include/linux/devfreq.h   |  9 +++++++++
>>   2 files changed, 25 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>> index bf3ea76..d1152eb 100644
>> --- a/drivers/devfreq/devfreq.c
>> +++ b/drivers/devfreq/devfreq.c
>> @@ -364,7 +364,10 @@ void devfreq_monitor_suspend(struct devfreq *devfreq)
>>   		return;
>>   	}
>>   
>> -	devfreq_update_status(devfreq, devfreq->previous_freq);
>> +	if (devfreq->suspend_freq)
>> +		devfreq_update_status(devfreq, devfreq->suspend_freq);
>> +	else
>> +		devfreq_update_status(devfreq, devfreq->previous_freq);
> This is incorrect.
>
> devfreq_update_status is to record the statistics.
> This code intends to record the current status before entering suspend;
> thus you should not record "suspend_freq" here.
>
> If you really need to record the frequency during suspended state
> for the statistics, you need to do that at resume; however, I object to
> that idea either.
>
> If you really want to set a predefined suspend-to-RAM mode frequency,
> (probably because of HW instability during resume process)
> you need to update, not udpate_status (statistics).
>
Thanks for pointing it, but if i use update_devfreq(), it can not 
specify the
frequency, it call the get_target_freq() to get the frequency and setting,
use now devfreq framework, it seems hard to set the specific freqeuency
when suspend. Do you have any idea, thanks.
>
>
> Cheers,
> MyungJoo
>

-- 
Lin Huang