cpufreq: qcom-hw: Fix probable nested interrupt handling

Re-enabling an interrupt from its own interrupt handler may cause
an interrupt storm, if there is a pending interrupt and because its
handling is disabled due to already done entrance into the handler
above in the stack.

Also, apparently it is improper to lock a mutex in an interrupt contex.

Fixes: 275157b367f4 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 63c11e7..5b609e2 100644 (file)
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -335,9 +335,9 @@ static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data)
 
        /* Disable interrupt and enable polling */
        disable_irq_nosync(c_data->throttle_irq);
-       qcom_lmh_dcvs_notify(c_data);
+       schedule_delayed_work(&c_data->throttle_work, 0);
 
-       return 0;
+       return IRQ_HANDLED;
 }
 
 static const struct qcom_cpufreq_soc_data qcom_soc_data = {