[PATCH v2 1/5] pinctrl: qcom: lpass-lpi: make mutex cleanup devm-managed

[Prasad Kumpatla]

The driver registers its pin controller using devm_pinctrl_register(),
which keeps the pinctrl device alive until devres teardown, after
.remove() returns. Explicitly destroying pctrl->lock in .remove() and
the probe error path leaves the mutex destroyed while the pinctrl
device is still accessible, risking a panic on concurrent debugfs
access during unbind.

Switch to devm_mutex_init() so the mutex lifetime is automatically
aligned with the devm-managed pinctrl device, and remove now
redundant mutex_destroy() calls and err_pinctrl label.

Signed-off-by: Prasad Kumpatla <prasad.kumpatla@xxxxxxxxxxxxxxxx>
---
 drivers/pinctrl/qcom/pinctrl-lpass-lpi.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
index 5fd4a4eba..b3e365470 100644
--- a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
+++ b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
@@ -559,31 +559,25 @@ int lpi_pinctrl_probe(struct platform_device *pdev)
 	pctrl->chip.label = dev_name(dev);
 	pctrl->chip.can_sleep = true;
 
-	mutex_init(&pctrl->lock);
+	ret = devm_mutex_init(&pdev->dev, &pctrl->lock);
+	if (ret)
+		return ret;
 
 	pctrl->ctrl = devm_pinctrl_register(dev, &pctrl->desc, pctrl);
-	if (IS_ERR(pctrl->ctrl)) {
-		ret = PTR_ERR(pctrl->ctrl);
-		dev_err(dev, "failed to add pin controller\n");
-		goto err_pinctrl;
-	}
+	if (IS_ERR(pctrl->ctrl))
+		return PTR_ERR(pctrl->ctrl);
 
 	ret = lpi_build_pin_desc_groups(pctrl);
 	if (ret)
-		goto err_pinctrl;
+		return ret;
 
 	ret = devm_gpiochip_add_data(dev, &pctrl->chip, pctrl);
 	if (ret) {
 		dev_err(pctrl->dev, "can't add gpio chip\n");
-		goto err_pinctrl;
+		return ret;
 	}
 
 	return 0;
-
-err_pinctrl:
-	mutex_destroy(&pctrl->lock);
-
-	return ret;
 }
 EXPORT_SYMBOL_GPL(lpi_pinctrl_probe);
 
@@ -592,8 +586,6 @@ void lpi_pinctrl_remove(struct platform_device *pdev)
 	struct lpi_pinctrl *pctrl = platform_get_drvdata(pdev);
 	int i;
 
-	mutex_destroy(&pctrl->lock);
-
 	for (i = 0; i < pctrl->data->npins; i++)
 		pinctrl_generic_remove_group(pctrl->ctrl, i);
 }
-- 
2.34.1