From: Mark Tseng <chun-jen.tseng@mediatek.com>
To: "Rafael J . Wysocki" <rafael@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
"Kyungmin Park" <kyungmin.park@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>
Cc: <linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>,
<Project_Global_Chrome_Upstream_Group@mediatek.com>,
<chun-jen.tseng@mediatek.com>
Subject: [PATCH v2 2/4] cpufreq: mediatek: using global lock avoid race condition
Date: Fri, 8 Nov 2024 14:39:40 +0800 [thread overview]
Message-ID: <20241108063942.19744-3-chun-jen.tseng@mediatek.com> (raw)
In-Reply-To: <20241108063942.19744-1-chun-jen.tseng@mediatek.com>
In mtk_cpufreq_set_target() is re-enter function but the mutex lock
decalre in mtk_cpu_dvfs_info structure for each policy. It should
change to global variable for critical session avoid race condition
with 2 or more policy.
add mtk_cpufreq_get() replace cpufreq_generic_get() and use global lock
avoid return wrong clock.
Signed-off-by: Mark Tseng <chun-jen.tseng@mediatek.com>
---
drivers/cpufreq/mediatek-cpufreq.c | 39 ++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 10 deletions(-)
diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index f63183154e9a..6b3cd2b803bf 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -49,8 +49,6 @@ struct mtk_cpu_dvfs_info {
bool need_voltage_tracking;
int vproc_on_boot;
int pre_vproc;
- /* Avoid race condition for regulators between notify and policy */
- struct mutex reg_lock;
struct notifier_block opp_nb;
unsigned int opp_cpu;
unsigned long current_freq;
@@ -59,6 +57,9 @@ struct mtk_cpu_dvfs_info {
bool ccifreq_bound;
};
+/* Avoid race condition for regulators between notify and policy */
+static DEFINE_MUTEX(mtk_policy_lock);
+
static struct platform_device *cpufreq_pdev;
static LIST_HEAD(dvfs_info_list);
@@ -209,12 +210,12 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
long freq_hz, pre_freq_hz;
int vproc, pre_vproc, inter_vproc, target_vproc, ret;
+ mutex_lock(&mtk_policy_lock);
+
inter_vproc = info->intermediate_voltage;
pre_freq_hz = clk_get_rate(cpu_clk);
- mutex_lock(&info->reg_lock);
-
if (unlikely(info->pre_vproc <= 0))
pre_vproc = regulator_get_voltage(info->proc_reg);
else
@@ -308,7 +309,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
info->current_freq = freq_hz;
out:
- mutex_unlock(&info->reg_lock);
+ mutex_unlock(&mtk_policy_lock);
return ret;
}
@@ -316,19 +317,20 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
- struct dev_pm_opp *opp = data;
+ struct dev_pm_opp *opp;
struct dev_pm_opp *new_opp;
struct mtk_cpu_dvfs_info *info;
unsigned long freq, volt;
struct cpufreq_policy *policy;
int ret = 0;
+ mutex_lock(&mtk_policy_lock);
+ opp = data;
info = container_of(nb, struct mtk_cpu_dvfs_info, opp_nb);
if (event == OPP_EVENT_ADJUST_VOLTAGE) {
freq = dev_pm_opp_get_freq(opp);
- mutex_lock(&info->reg_lock);
if (info->current_freq == freq) {
volt = dev_pm_opp_get_voltage(opp);
ret = mtk_cpufreq_set_voltage(info, volt);
@@ -336,7 +338,6 @@ static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
dev_err(info->cpu_dev,
"failed to scale voltage: %d\n", ret);
}
- mutex_unlock(&info->reg_lock);
} else if (event == OPP_EVENT_DISABLE) {
freq = dev_pm_opp_get_freq(opp);
@@ -361,6 +362,7 @@ static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
}
}
}
+ mutex_unlock(&mtk_policy_lock);
return notifier_from_errno(ret);
}
@@ -495,7 +497,6 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
- mutex_init(&info->reg_lock);
info->current_freq = clk_get_rate(info->cpu_clk);
info->opp_cpu = cpu;
@@ -610,13 +611,31 @@ static void mtk_cpufreq_exit(struct cpufreq_policy *policy)
dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
}
+static unsigned int mtk_cpufreq_get(unsigned int cpu)
+{
+ struct mtk_cpu_dvfs_info *info;
+ unsigned long current_freq;
+
+ mutex_lock(&mtk_policy_lock);
+ info = mtk_cpu_dvfs_info_lookup(cpu);
+ if (!info) {
+ mutex_unlock(&mtk_policy_lock);
+ return 0;
+ }
+
+ current_freq = info->current_freq / 1000;
+ mutex_unlock(&mtk_policy_lock);
+
+ return current_freq;
+}
+
static struct cpufreq_driver mtk_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
CPUFREQ_IS_COOLING_DEV,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = mtk_cpufreq_set_target,
- .get = cpufreq_generic_get,
+ .get = mtk_cpufreq_get,
.init = mtk_cpufreq_init,
.exit = mtk_cpufreq_exit,
.register_em = cpufreq_register_em_with_opp,
--
2.45.2
next prev parent reply other threads:[~2024-11-08 6:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-08 6:39 [PATCH v2 0/4] fixed mediatek-cpufreq has multi policy concurrency issue Mark Tseng
2024-11-08 6:39 ` [PATCH v2 1/4] cpufreq: mediatek: CCI support SoC , the transition_delay set to 10 ms Mark Tseng
2024-11-14 10:22 ` AngeloGioacchino Del Regno
2025-02-14 7:41 ` Chun-Jen Tseng (曾俊仁)
2024-11-08 6:39 ` Mark Tseng [this message]
2024-11-08 6:39 ` [PATCH v2 3/4] cpufreq: mediatek: Add CPUFREQ_ASYNC_NOTIFICATION flag Mark Tseng
2024-11-08 6:39 ` [PATCH v2 4/4] cpufreq: mediatek: data safety protect Mark Tseng
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=20241108063942.19744-3-chun-jen.tseng@mediatek.com \
--to=chun-jen.tseng@mediatek.com \
--cc=Project_Global_Chrome_Upstream_Group@mediatek.com \
--cc=angelogioacchino.delregno@collabora.com \
--cc=cw00.choi@samsung.com \
--cc=kyungmin.park@samsung.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-pm@vger.kernel.org \
--cc=matthias.bgg@gmail.com \
--cc=myungjoo.ham@samsung.com \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.