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From: Andy Tang <andy.tang@nxp.com>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "rjw@rjwysocki.net" <rjw@rjwysocki.net>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Subject: RE: [EXT] Re: Ask for help about cpufreq issue
Date: Tue, 11 Feb 2020 06:23:01 +0000	[thread overview]
Message-ID: <VI1PR04MB4333D6A41BD1AB77489E3139F3180@VI1PR04MB4333.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <20200211055315.qlqrxiqf72u36ijl@vireshk-i7>

Thanks for your instruction. I guess it was caused by QOS.
I try to change scaling_max_freq. it can be written, but have no effect.

I am going to track to dev_pm_qos_add_request() as you suggested.
Before that, I am also wondering what the factor it could be to limit the cpu max frequency?

BR,
Andy

> -----Original Message-----
> From: Viresh Kumar <viresh.kumar@linaro.org>
> Sent: 2020年2月11日 13:53
> To: Andy Tang <andy.tang@nxp.com>
> Cc: rjw@rjwysocki.net; linux-pm@vger.kernel.org
> Subject: Re: [EXT] Re: Ask for help about cpufreq issue
> 
> Caution: EXT Email
> 
> On 11-02-20, 04:20, Andy Tang wrote:
> > Hi Viresh,
> >
> > I checked the clk part, no issue was found.
> > I did found a odd thing in cpufreq directory.
> >
> > # cat scaling_available_frequencies
> > 1600000 1000000 800000 500000
> > # cat scaling_max_freq
> > 500000
> 
> Ahh, sorry about that as I must have noticed it earlier.
> 
> > Why there is a 1600Mhz frequency available, but the max freq is only
> 500M?
> > How the max freq is set?
> 
> Hmm, I am not sure why this happened. Can you try to write 1600000 to
> scaling_max_freq? This will fix it if the userspace is responsible for this
> limitation and you need to find which part of your userspace is causing it.
> 
> Else this is coming from within kernel and you need to track calls to
> dev_pm_qos_add_request() and check all calls related to freq qos
> constraints.
> 
> --
> viresh

  reply	other threads:[~2020-02-11  6:23 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-07  5:09 Ask for help about cpufreq issue Andy Tang
2020-02-07  5:23 ` Viresh Kumar
2020-02-07  6:03   ` [EXT] " Andy Tang
2020-02-07  7:05     ` Viresh Kumar
2020-02-11  4:20       ` Andy Tang
2020-02-11  5:53         ` Viresh Kumar
2020-02-11  6:23           ` Andy Tang [this message]
2020-02-11  6:34             ` Viresh Kumar
2020-02-11  7:20               ` Andy Tang
2020-02-12 10:11               ` Andy Tang
2020-02-12 11:50                 ` Viresh Kumar
2020-02-13  8:18                   ` Andy Tang
2020-02-13  8:48                     ` Viresh Kumar
2020-02-13  9:12                       ` Andy Tang
2020-02-13  9:15                         ` Viresh Kumar
2020-02-13  9:21                           ` Andy Tang
2020-02-14 10:00                       ` Andy Tang
2020-02-17  8:22                         ` Viresh Kumar

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