From: Schspa Shi <schspa@gmail.com>
To: rafael@kernel.org, viresh.kumar@linaro.org
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, schspa@gmail.com
Subject: [PATCH v6 2/2] cpufreq: make interface functions and lock holding state clear
Date: Mon, 16 May 2022 11:02:51 +0800 [thread overview]
Message-ID: <20220516030251.42323-2-schspa@gmail.com> (raw)
In-Reply-To: <20220516030251.42323-1-schspa@gmail.com>
cpufreq_offline() calls offline() and exit() under the policy rwsem
But they are called outside the rwsem in cpufreq_online().
This patch move the offline(), exit(), online(), init() to be inside
of policy rwsem to achieve a clear lock relationship.
All the init() online() implement only initialize policy object without
holding this lock and won't call cpufreq APIs need to hold this lock.
Signed-off-by: Schspa Shi <schspa@gmail.com>
---
drivers/cpufreq/cpufreq.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ba73be6f0490..ccb774e02934 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1339,12 +1339,12 @@ static int cpufreq_online(unsigned int cpu)
down_write(&policy->rwsem);
policy->cpu = cpu;
policy->governor = NULL;
- up_write(&policy->rwsem);
} else {
new_policy = true;
policy = cpufreq_policy_alloc(cpu);
if (!policy)
return -ENOMEM;
+ down_write(&policy->rwsem);
}
if (!new_policy && cpufreq_driver->online) {
@@ -1384,7 +1384,6 @@ static int cpufreq_online(unsigned int cpu)
cpumask_copy(policy->related_cpus, policy->cpus);
}
- down_write(&policy->rwsem);
/*
* affected cpus must always be the one, which are online. We aren't
* managing offline cpus here.
@@ -1536,7 +1535,6 @@ static int cpufreq_online(unsigned int cpu)
remove_cpu_dev_symlink(policy, get_cpu_device(j));
cpumask_clear(policy->cpus);
- up_write(&policy->rwsem);
out_offline_policy:
if (cpufreq_driver->offline)
@@ -1547,6 +1545,8 @@ static int cpufreq_online(unsigned int cpu)
cpufreq_driver->exit(policy);
out_free_policy:
+ up_write(&policy->rwsem);
+
cpufreq_policy_free(policy);
return ret;
}
--
2.29.0
next prev parent reply other threads:[~2022-05-16 3:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-16 3:02 [PATCH v6 1/2] cpufreq: Abort show/store for half initialized policy Schspa Shi
2022-05-16 3:02 ` Schspa Shi [this message]
2022-05-16 10:25 ` [PATCH v6 2/2] cpufreq: make interface functions and lock holding state clear Viresh Kumar
2022-05-16 10:24 ` [PATCH v6 1/2] cpufreq: Abort show/store for half initialized policy Viresh Kumar
2022-05-17 19:40 ` Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220516030251.42323-2-schspa@gmail.com \
--to=schspa@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=rafael@kernel.org \
--cc=viresh.kumar@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).