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From:   Stephen Boyd <swboyd@chromium.org>
To:     Viresh Kumar <viresh.kumar@linaro.org>
Cc:     linux-kernel@vger.kernel.org, patches@lists.linux.dev,
        linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Rob Clark <robdclark@chromium.org>,
        Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Subject: [PATCH] cpufreq: qcom-hw: Don't do lmh things without a throttle interrupt
Date:   Thu, 16 Jun 2022 15:45:31 -0700
Message-Id: <20220616224531.3139080-1-swboyd@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Offlining cpu6 and cpu7 and then onlining cpu6 hangs on
sc7180-trogdor-lazor because the throttle interrupt doesn't exist.
Similarly, things go sideways when suspend/resume runs. That's because
the qcom_cpufreq_hw_cpu_online() and qcom_cpufreq_hw_lmh_exit()
functions are calling genirq APIs with an interrupt value of '-6', i.e.
-ENXIO, and that isn't good.

Check the value of the throttle interrupt like we already do in other
functions in this file and bail out early from lmh code to fix the hang.

Reported-by: Rob Clark <robdclark@chromium.org>
Cc: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Fixes: a1eb080a0447 ("cpufreq: qcom-hw: provide online/offline operations")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 0253731d6d25..36c79580fba2 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -442,6 +442,9 @@ static int qcom_cpufreq_hw_cpu_online(struct cpufreq_policy *policy)
 	struct platform_device *pdev = cpufreq_get_driver_data();
 	int ret;
 
+	if (data->throttle_irq <= 0)
+		return 0;
+
 	ret = irq_set_affinity_hint(data->throttle_irq, policy->cpus);
 	if (ret)
 		dev_err(&pdev->dev, "Failed to set CPU affinity of %s[%d]\n",
@@ -469,6 +472,9 @@ static int qcom_cpufreq_hw_cpu_offline(struct cpufreq_policy *policy)
 
 static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data)
 {
+	if (data->throttle_irq <= 0)
+		return;
+
 	free_irq(data->throttle_irq, data);
 }
 

base-commit: f2906aa863381afb0015a9eb7fefad885d4e5a56
-- 
https://chromeos.dev