releases/6.10.5/soc-qcom-icc-bwmon-allow-for-interrupts-to-be-shared.patch

From c0664fb300408b27a12b709a39a168c2e3c3cd07 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Mon, 24 Jun 2024 14:52:13 +0530
Subject: soc: qcom: icc-bwmon: Allow for interrupts to be shared across
 instances

From: Sibi Sankar <quic_sibis@quicinc.com>

[ Upstream commit dc18836435e7f8dda019db2c618c69194933157f ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 ecddb60bd6650..e7851974084b6 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 = {
-- 
2.43.0