Thread (12 messages) read the whole thread 12 messages, 5 authors, 2021-11-25
STALE1709d

[PATCH 2/3] cpufreq: qcom-hw: Fix probable nested interrupt handling

From: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Date: 2021-11-11 15:48:26
Also in: linux-arm-msm
Subsystem: arm/qualcomm mailing list, cpu frequency scaling framework, the rest · Maintainers: "Rafael J. Wysocki", Viresh Kumar, Linus Torvalds

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>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 3b5835336658..5d55217caa8b 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -343,9 +343,9 @@ 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 = {
-- 
2.32.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help