From: Viresh Kumar <viresh.kumar@linaro.org>
To: Steev Klimaszewski <steev@kali.org>
Cc: Thara Gopinath <thara.gopinath@linaro.org>,
rafael@kernel.org, bjorn.andersson@linaro.org,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] cpufreq: freq_table: Initialize cpuinfo.max_freq to correct max frequency.
Date: Tue, 16 Nov 2021 09:29:35 +0530 [thread overview]
Message-ID: <20211116035935.wmazontuznhys6qu@vireshk-i7> (raw)
In-Reply-To: <5ae2c644-4743-c62c-b17c-96945a0e6a01@kali.org>
On 15-11-21, 19:23, Steev Klimaszewski wrote:
> Hi Thara,
>
> On 11/15/21 1:50 PM, Thara Gopinath wrote:
> > cpuinfo.max_freq reflects the maximum supported frequency of cpus in a
> > cpufreq policy. When cpus support boost frequency and if boost is disabled
> > during boot up (which is the default), cpuinfo.max_freq does not reflect
> > boost frequency as the maximum supported frequency till boost is explicitly
> > enabled via sysfs interface later. This also means that policy reports two
> > different cpuinfo.max_freq before and after turning on boost. Fix this by
> > separating out setting of policy->max and cpuinfo.max_freq in
> > cpufreq_frequency_table_cpuinfo.
> >
> > e.g. of the problem. Qualcomm sdm845 supports boost frequency for gold
> > cluster (cpus 4-7). After boot up (boost disabled),
> >
> > 1. cat /sys/devices/system/cpu/cpufreq/policy4/cpuinfo_max_freq 2649600
> > <- This is wrong because boost frequency is
> >
> > 2. echo 1 > /sys/devices/system/cpu/cpufreq/boost <- Enable boost cat
> > /sys/devices/system/cpu/cpufreq/policy4/cpuinfo_max_freq 2803200 <-
> > max freq reflects boost freq.
> >
> > 3. echo 0 > /sys/devices/system/cpu/cpufreq/boost <- Disable boost cat
> > /sys/devices/system/cpu/cpufreq/policy4/cpuinfo_max_freq 2803200 <-
> > Discrepancy with step 1 as in both cases boost is disabled.
> >
> > Note that the other way to fix this is to set cpuinfo.max_freq in Soc
> > cpufreq driver during initialization. Fixing it in
> > cpufreq_frequency_table_cpuinfo seems more generic solution
> >
> > Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
> > ---
> > drivers/cpufreq/freq_table.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
> > index 67e56cf638ef..6784f94124df 100644
> > --- a/drivers/cpufreq/freq_table.c
> > +++ b/drivers/cpufreq/freq_table.c
> > @@ -35,11 +35,15 @@ int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
> > struct cpufreq_frequency_table *pos;
> > unsigned int min_freq = ~0;
> > unsigned int max_freq = 0;
> > + unsigned int cpuinfo_max_freq = 0;
> > unsigned int freq;
> > cpufreq_for_each_valid_entry(pos, table) {
> > freq = pos->frequency;
> > + if (freq > cpuinfo_max_freq)
> > + cpuinfo_max_freq = freq;
> > +
> > if (!cpufreq_boost_enabled()
> > && (pos->flags & CPUFREQ_BOOST_FREQ))
> > continue;
> > @@ -57,8 +61,8 @@ int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
> > * If the driver has set its own cpuinfo.max_freq above max_freq, leave
> > * it as is.
> > */
> > - if (policy->cpuinfo.max_freq < max_freq)
> > - policy->max = policy->cpuinfo.max_freq = max_freq;
> > + if (policy->cpuinfo.max_freq < cpuinfo_max_freq)
> > + policy->cpuinfo.max_freq = cpuinfo_max_freq;
You need to keep the check of policy->max here and update policy->max,
else you will never run at boost freq. I think this is what Steev
reported as well ?
So basically something like this:
if (policy->max < max_freq)
policy->max = max_freq;
if (policy->cpuinfo.max_freq < cpuinfo_max_freq)
policy->cpuinfo.max_freq = cpuinfo_max_freq;
--
viresh
next prev parent reply other threads:[~2021-11-16 5:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-15 19:50 [PATCH] cpufreq: freq_table: Initialize cpuinfo.max_freq to correct max frequency Thara Gopinath
2021-11-16 1:23 ` Steev Klimaszewski
2021-11-16 3:00 ` Steev Klimaszewski
2021-11-16 3:59 ` Viresh Kumar [this message]
2021-11-16 15:27 ` Thara Gopinath
2021-11-17 7:24 ` Viresh Kumar
2021-11-16 15:31 ` Thara Gopinath
2021-11-16 16:15 ` Steev Klimaszewski
2021-11-16 16:44 ` Steev Klimaszewski
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