linux-kernel - Re: [PATCH v3 2/3] cpufreq: mediatek: Add CPUFREQ_ASYNC

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Message-ID: <21e1b622c2968a5549b2ff37e4ba329a557968b6.camel@mediatek.com>
Date: Thu, 20 Mar 2025 08:34:51 +0000
From: Chun-Jen Tseng (曾俊仁)
	<Chun-Jen.Tseng@...iatek.com>
To: "viresh.kumar@...aro.org" <viresh.kumar@...aro.org>
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Subject: Re: [PATCH v3 2/3] cpufreq: mediatek: Add CPUFREQ_ASYNC_NOTIFICATION
 flag

Hi viresh,

For CCI and ARMPLL in different driver, I need to change ARMPLL first
then use cpufreq notify CCI driver. it can avoid CCI driver get wrong
ARMPLL frequency and choose WRONG frequency.

BRs,

Mark Tseng


On Wed, 2025-02-19 at 11:15 +0530, Viresh Kumar wrote:
> 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> On 14-02-25, 15:43, Mark Tseng wrote:
> > Add CPUFREQ_ASYNC_NOTIFICATION flages for cpufreq policy because
> > some of
> > process will get CPU frequency by cpufreq sysfs node. It may get
> > wrong
> > frequency then call cpufreq_out_of_sync() to fixed frequency.
> 
> That's not why CPUFREQ_ASYNC_NOTIFICATION is used. It is used only
> for the cases
> where the target()/target_index() callback defers the work to some
> other entity
> (like a workqueue) and it is not guaranteed that the frequency will
> be changed
> before these helpers return.
> 
> I don't think your patch is required.
> 
> --
> viresh