From: Viresh Kumar <viresh.kumar@linaro.org>
To: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: linux-omap@vger.kernel.org,
Vincent Guittot <vincent.guittot@linaro.org>,
Kevin Hilman <khilman@kernel.org>,
linux-tegra@vger.kernel.org, linux-mips@vger.kernel.org,
linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org,
Rafael Wysocki <rjw@rjwysocki.net>,
linux-kernel@vger.kernel.org,
Krzysztof Kozlowski <krzk@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
linux-samsung-soc@vger.kernel.org, Andy Gross <agross@kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Sudeep Holla <sudeep.holla@arm.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-mediatek@lists.infradead.org,
Jonathan Hunter <jonathanh@nvidia.com>,
Keguang Zhang <keguang.zhang@gmail.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] cpufreq: Remove CPUFREQ_STICKY flag
Date: Mon, 1 Feb 2021 15:35:02 +0530 [thread overview]
Message-ID: <20210201100502.xluaj5rpqosqsq7b@vireshk-i7> (raw)
In-Reply-To: <YBfNb91psVcf3TAS@light.dominikbrodowski.net>
On 01-02-21, 10:44, Dominik Brodowski wrote:
> IIRC, it was required on various ARM systems,[*] as CPUs were registered as
> subsys_initcall(), while cpufreq used to be initialized only later, as an
s/later/earlier ? arch happens before subsys not at least and that is
the only way we can break cpufreq here, i.e. when the driver comes up
before the CPUs are registered.
> arch_initcall(). If the ordering is opposite now on all architectures (it
> wasn't on ARM back then), we should be fine.
>
> [*] https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/arch/arm/mach-sa1100/cpu-sa1100.c?id=f59d3bbe35f6268d729f51be82af8325d62f20f5
Thanks for your reply, it made me look at that aspect in some more
detail to confirm I don't end up breaking anything. Unless I am making
a mistake in reading the code, this is the code flow that we have
right now:
start_kernel()
-> kernel_init()
-> kernel_init_freeable()
-> do_basic_setup()
-> driver_init()
-> cpu_dev_init()
-> subsys_system_register(for-CPUs)
-> do_initcalls()
-> register-cpufreq-driver from any level
And so CPUs should always be there for a cpufreq driver.
Makes sense ?
--
viresh
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next prev parent reply other threads:[~2021-02-01 10:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 8:05 [PATCH] cpufreq: Remove CPUFREQ_STICKY flag Viresh Kumar
2021-02-01 9:44 ` Dominik Brodowski
2021-02-01 10:05 ` Viresh Kumar [this message]
2021-02-01 14:02 ` Rafael J. Wysocki
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