The multiple BWMONv4 instances available on the X1E80100 SoC use the
same interrupt number. Mark them are shared to allow for re-use across
instances.
Using IRQF_SHARED coupled with devm_request_threaded_irq implies that
the irq can still trigger during/after bwmon_remove due to other active
bwmon instances. Handle this race by relying on bwmon_disable to disable
the interrupt and coupled with explicit request/free irqs.
Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
---
v3:
* Update commit message describing the race condition. [Bjorn]
* Update comment in the bwmon driver. [Dmitry]
drivers/soc/qcom/icc-bwmon.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/soc/qcom/icc-bwmon.c b/drivers/soc/qcom/icc-bwmon.c
index ecddb60bd665..e7851974084b 100644
--- a/drivers/soc/qcom/icc-bwmon.c
+++ b/drivers/soc/qcom/icc-bwmon.c
@@ -783,9 +783,14 @@ static int bwmon_probe(struct platform_device *pdev)
bwmon->dev = dev;
bwmon_disable(bwmon);
- ret = devm_request_threaded_irq(dev, bwmon->irq, bwmon_intr,
- bwmon_intr_thread,
- IRQF_ONESHOT, dev_name(dev), bwmon);
+
+ /*
+ * SoCs with multiple cpu-bwmon instances can end up using a shared interrupt
+ * line. Using the devm_ variant might result in the IRQ handler being executed
+ * after bwmon_disable in bwmon_remove()
+ */
+ ret = request_threaded_irq(bwmon->irq, bwmon_intr, bwmon_intr_thread,
+ IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), bwmon);
if (ret)
return dev_err_probe(dev, ret, "failed to request IRQ\n");
@@ -800,6 +805,7 @@ static void bwmon_remove(struct platform_device *pdev)
struct icc_bwmon *bwmon = platform_get_drvdata(pdev);
bwmon_disable(bwmon);
+ free_irq(bwmon->irq, bwmon);
}
static const struct icc_bwmon_data msm8998_bwmon_data = {
--
2.34.1
