From: andrew-sh.cheng <andrew-sh.cheng@mediatek.com>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Mark Rutland" <mark.rutland@arm.com>,
"Nishanth Menon" <nm@ti.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
srv_heupstream <srv_heupstream@mediatek.com>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"Stephen Boyd" <sboyd@kernel.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Chanwoo Choi" <cw00.choi@samsung.com>,
"Kyungmin Park" <kyungmin.park@samsung.com>,
"Rob Herring" <robh+dt@kernel.org>,
"linux-mediatek@lists.infradead.org"
<linux-mediatek@lists.infradead.org>,
"MyungJoo Ham" <myungjoo.ham@samsung.com>,
"Matthias Brugger" <matthias.bgg@gmail.com>,
"Fan Chen (陳凡)" <fan.chen@mediatek.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [v5, PATCH 4/5] cpufreq: mediatek: add opp notification for SVS support
Date: Fri, 13 Mar 2020 15:22:34 +0800 [thread overview]
Message-ID: <1584084154.7753.3.camel@mtksdaap41> (raw)
In-Reply-To: <20200311060616.62nh7sfwtjwvrjfr@vireshk-i7>
On Wed, 2020-03-11 at 11:36 +0530, Viresh Kumar wrote:
> On 10-03-20, 16:11, andrew-sh.cheng wrote:
> > On Tue, 2019-12-10 at 14:43 +0800, Viresh Kumar wrote:
> > > On 09-12-19, 14:56, andrew-sh.cheng wrote:
> > > > On Wed, 2019-11-27 at 14:06 +0530, Viresh Kumar wrote:
> > > > > On 26-11-19, 19:50, Andrew-sh.Cheng wrote:
> > > > > > + if (!IS_ERR(opp_item))
> > > > > > + dev_pm_opp_put(opp_item);
> > > > > > + else
> > > > > > + freq = 0;
> > > > > > +
> > > > >
> > > > > What is the purpose of the above code ?
> > > > When dev_pm_opp_find_freq_ceil() doesn't find matching opp item, freq
> > > > value won't be set.
> > > > Set it as 0 for below checking
> > > > >
> > > > > > + /* case of current opp is disabled */
> > > > > > + if (freq == 0 || freq != info->opp_freq) {
> > > > > > + // find an enable opp item
> > > > > > + freq = 1;
> > > > > > + opp_item = dev_pm_opp_find_freq_ceil(info->cpu_dev,
> > > > > > + &freq);
> > > > > > + if (!IS_ERR(opp_item)) {
> > > > > > + dev_pm_opp_put(opp_item);
> > > > > > + policy = cpufreq_cpu_get(info->opp_cpu);
> > > > > > + if (policy) {
> > > > > > + cpufreq_driver_target(policy,
> > > > > > + freq / 1000,
> > > > > > + CPUFREQ_RELATION_L);
> > > > >
> > > > > Why don't you simply call this instead of all the code in the else
> > > > > block ?
> > > > These else code is used to check "current opp item is disabled or not".
> > > > If not, do nothing.
> > > > If current opp item is disabled, need to find an not-disabled opp item,
> > > > and set frequency to it.
> > >
> > > Right. So this notifier helper of yours receive the opp which is getting
> > > disabled, why don't you compare its frequency directly to see if the current OPP
> > > is getting disabled ?
> > Sorry to overlook your question.
> > This is because when the opp is disabled,
> > we cannot use dev_pm_opp_get_freq() to get frequency of that opp.
> > There is a check:
> > if (IS_ERR_OR_NULL(opp) || !opp->available) {
>
> I think we can remove the available check here, as we are jut trying
> to find frequency of an OPP we already have. Send a patch for that
> please.
>
Hi Viresh,
I have something want to consult you.
For your previous comment, you suggest use read-write lock to replace
mutex lock.
Will it be more efficiently even when all are write lock?
(all lock region are "setting VProc voltage")
> > pr_err("%s: Invalid parameters\n", __func__);
> > return 0;
> >
> > >
> >
>
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next prev parent reply other threads:[~2020-03-13 7:22 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20191126115058epcas1p3caa6da2508caa5fbe71c202834184b15@epcas1p3.samsung.com>
2019-11-26 11:50 ` [v5, PATCH 0/5] Add cpufreq and cci devfreq for mt8183, and SVS support Andrew-sh.Cheng
2019-11-26 11:50 ` [v5, PATCH 1/5] cpufreq: mediatek: add clock enable for intermediate clock Andrew-sh.Cheng
2019-11-26 11:50 ` [v5, PATCH 2/5] dt-bindings: devfreq: add compatible for mt8183 cci devfreq Andrew-sh.Cheng
2019-12-17 2:38 ` Chanwoo Choi
2019-11-26 11:50 ` [v5, PATCH 3/5] devfreq: add mediatek " Andrew-sh.Cheng
2019-12-17 10:08 ` Chanwoo Choi
2019-11-26 11:50 ` [v5, PATCH 4/5] cpufreq: mediatek: add opp notification for SVS support Andrew-sh.Cheng
2019-11-27 8:36 ` Viresh Kumar
2019-12-09 6:56 ` andrew-sh.cheng
2019-12-10 6:43 ` Viresh Kumar
2020-03-10 8:11 ` andrew-sh.cheng
2020-03-11 6:06 ` Viresh Kumar
2020-03-12 9:12 ` andrew-sh.cheng
2020-03-13 7:22 ` andrew-sh.cheng [this message]
2020-03-13 9:10 ` Viresh Kumar
2020-04-06 9:12 ` andrew-sh.cheng
2020-04-06 9:29 ` Viresh Kumar
2020-04-07 6:54 ` andrew-sh.cheng
2020-04-07 8:29 ` Viresh Kumar
2020-04-07 9:09 ` andrew-sh.cheng
2019-11-26 11:50 ` [v5, PATCH 5/5] devfreq: mediatek: cci devfreq register " Andrew-sh.Cheng
2019-12-17 7:31 ` [v5, PATCH 0/5] Add cpufreq and cci devfreq for mt8183, and " Chanwoo Choi
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