From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael Wysocki <rjw@rjwysocki.net>,
Linux PM <linux-pm@vger.kernel.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/6] cpufreq: Replace few CPUFREQ_CONST_LOOPS checks with has_target()
Date: Wed, 19 Jun 2019 14:20:18 +0200 [thread overview]
Message-ID: <CAJZ5v0g1avBwjezWpMimGbs1NHOchib9pmTKoxaixKtpw_CGJw@mail.gmail.com> (raw)
In-Reply-To: <0660b023a0d80c63ec7a1f7fcb692de9a9f4d604.1560944014.git.viresh.kumar@linaro.org>
On Wed, Jun 19, 2019 at 1:36 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> CPUFREQ_CONST_LOOPS was introduced in a very old commit from pre-2.6
> kernel release commit 6a4a93f9c0d5 ("[CPUFREQ] Fix 'out of sync'
> issue").
>
> Probably the initial idea was to just avoid these checks for set_policy
> type drivers and then things got changed over the years. And it is very
> unclear why these checks are there at all.
>
> Replace the CPUFREQ_CONST_LOOPS check with has_target(), which makes
> more sense now.
>
> Also remove () around freq comparison statement as they aren't required
> and checkpatch also warns for them.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> drivers/cpufreq/cpufreq.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 54befd775bd6..e59194c2c613 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -359,12 +359,10 @@ static void cpufreq_notify_transition(struct cpufreq_policy *policy,
> * which is not equal to what the cpufreq core thinks is
> * "old frequency".
> */
> - if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
> - if (policy->cur && (policy->cur != freqs->old)) {
> - pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
> - freqs->old, policy->cur);
> - freqs->old = policy->cur;
> - }
> + if (has_target() && policy->cur && policy->cur != freqs->old) {
> + pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
> + freqs->old, policy->cur);
> + freqs->old = policy->cur;
Is cpufreq_notify_transition() ever called if ->setpolicy drivers are in use?
> }
>
> srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
> @@ -1618,8 +1616,7 @@ static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
> if (policy->fast_switch_enabled)
> return ret_freq;
>
> - if (ret_freq && policy->cur &&
> - !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
> + if (has_target() && ret_freq && policy->cur) {
> /* verify no discrepancy between actual and
> saved value exists */
> if (unlikely(ret_freq != policy->cur)) {
> --
> 2.21.0.rc0.269.g1a574e7a288b
>
next prev parent reply other threads:[~2019-06-19 12:20 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 11:35 [PATCH 0/6] cpufreq: cleanups Viresh Kumar
2019-06-19 11:35 ` [PATCH 1/6] cpufreq: Remove the redundant !setpolicy check Viresh Kumar
2019-06-19 11:35 ` [PATCH 2/6] cpufreq: Replace few CPUFREQ_CONST_LOOPS checks with has_target() Viresh Kumar
2019-06-19 12:20 ` Rafael J. Wysocki [this message]
2019-06-19 14:18 ` Viresh Kumar
2019-06-19 11:35 ` [PATCH 3/6] cpufreq: Remove the has_target() check from notifier handler Viresh Kumar
2019-06-19 12:25 ` Rafael J. Wysocki
2019-06-19 14:19 ` Viresh Kumar
2019-06-19 11:35 ` [PATCH 4/6] cpufreq: Use has_target() instead of !setpolicy Viresh Kumar
2019-06-19 12:28 ` Rafael J. Wysocki
2019-06-19 14:20 ` Viresh Kumar
2019-06-19 11:35 ` [PATCH 5/6] cpufreq: Reuse cpufreq_update_current_freq() in __cpufreq_get() Viresh Kumar
2019-06-19 11:35 ` [PATCH 6/6] cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update() Viresh Kumar
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