linux-kernel - [PATCH 2/4] cpufreq: qcom-hw: Disable LMH irq when disabling policy

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Date:   Wed, 15 Jun 2022 16:43:19 +0200
From:   Pierre Gondois <pierre.gondois@....com>
To:     linux-kernel@...r.kernel.org
Cc:     Ionela.Voinescu@....com, Lukasz.Luba@....com,
        Dietmar.Eggemann@....com, Pierre Gondois <pierre.gondois@....com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        linux-pm@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: [PATCH 2/4] cpufreq: qcom-hw: Disable LMH irq when disabling policy

If LMH (Limits Management Hardware) is available, when a policy is
disabled by unplugging the last online CPU of policy->cpus, the LMH
irq is left enabled.
When the policy is re-enabled with any of the CPU in policy->cpus
being plugged in, qcom_cpufreq_ready() re-enables the irq. This
triggers the following warning:
[  379.160106] Unbalanced enable for IRQ 154
[  379.160120] WARNING: CPU: 7 PID: 48 at kernel/irq/manage.c:774 __enable_irq+0x84/0xc0
Thus disable the irq.

This patch also makes the check against throttle_irq consistent,
0 being theoretically valid.

Fixes: a1eb080a0447 ("cpufreq: qcom-hw: provide online/offline operations")
Signed-off-by: Pierre Gondois <pierre.gondois@....com>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 8aba73698eda..8cad3744cff4 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -461,7 +461,7 @@ static int qcom_cpufreq_hw_cpu_offline(struct cpufreq_policy *policy)
 {
 	struct qcom_cpufreq_data *data = policy->driver_data;
 
-	if (data->throttle_irq <= 0)
+	if (data->throttle_irq < 0)
 		return 0;
 
 	mutex_lock(&data->throttle_lock);
@@ -470,6 +470,7 @@ static int qcom_cpufreq_hw_cpu_offline(struct cpufreq_policy *policy)
 
 	cancel_delayed_work_sync(&data->throttle_work);
 	irq_set_affinity_hint(data->throttle_irq, NULL);
+	disable_irq_nosync(data->throttle_irq);
 
 	return 0;
 }
-- 
2.25.1