soc: qcom: icc-bwmon: Allow for interrupts to be shared across instances

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@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20240624092214.146935-4-quic_sibis@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/drivers/soc/qcom/icc-bwmon.c b/drivers/soc/qcom/icc-bwmon.c
index ecddb60bd66509b9ebda8653aec74b5ab375e475..e7851974084b657f24a5bb3b049651dd27b9ef50 100644 (file)
--- 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 = {