[PATCH v4 1/2] counter: ti-eqep: Fix runtime PM leak on probe failure

[phucduc.bui@gmail.com]

From: Stepan Ionichev <sozdayvek@gmail.com>

ti_eqep_probe() enables runtime PM and takes a usage reference manually,
then returns directly via dev_err_probe() if devm_clk_get_enabled()
fails, leaking both.

Manual cleanup via goto would mix managed and unmanaged resources,
which leads to the wrong release order. Instead, use
devm_pm_runtime_enable() and pm_runtime_resume_and_get() with a devm
action for the put, so every probe error path unwinds in the correct
reverse order. As a side effect, a runtime resume failure now aborts
the probe instead of being ignored.

ti_eqep_remove() no longer needs to touch runtime PM. While at it,
report counter_add() failures with dev_err_probe().

Fixes: f213729f6796 ("counter: new TI eQEP driver")
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
[phuc: reworded commit message]
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---

v4:
 - Reword commit message of patch as suggested by Andy

 drivers/counter/ti-eqep.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
index 0dda3f2b14c7..2326515d5585 100644
--- a/drivers/counter/ti-eqep.c
+++ b/drivers/counter/ti-eqep.c
@@ -491,6 +491,11 @@ static const struct regmap_config ti_eqep_regmap16_config = {
 	.max_register = QCPRDLAT,
 };
 
+static void ti_eqep_pm_put(void *dev)
+{
+	pm_runtime_put_sync(dev);
+}
+
 static int ti_eqep_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -543,19 +548,25 @@ static int ti_eqep_probe(struct platform_device *pdev)
 	 * parent PWMSS bus driver. On AM17xx, this comes from the PSC power
 	 * domain.
 	 */
-	pm_runtime_enable(dev);
-	pm_runtime_get_sync(dev);
+	err = devm_pm_runtime_enable(dev);
+	if (err)
+		return err;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err)
+		return err;
+
+	err = devm_add_action_or_reset(dev, ti_eqep_pm_put, dev);
+	if (err)
+		return err;
 
 	clk = devm_clk_get_enabled(dev, NULL);
 	if (IS_ERR(clk))
 		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable clock\n");
 
 	err = counter_add(counter);
-	if (err < 0) {
-		pm_runtime_put_sync(dev);
-		pm_runtime_disable(dev);
-		return err;
-	}
+	if (err < 0)
+		return dev_err_probe(dev, err, "failed to add counter\n");
 
 	return 0;
 }
@@ -563,11 +574,8 @@ static int ti_eqep_probe(struct platform_device *pdev)
 static void ti_eqep_remove(struct platform_device *pdev)
 {
 	struct counter_device *counter = platform_get_drvdata(pdev);
-	struct device *dev = &pdev->dev;
 
 	counter_unregister(counter);
-	pm_runtime_put_sync(dev);
-	pm_runtime_disable(dev);
 }
 
 static const struct of_device_id ti_eqep_of_match[] = {
-- 
2.43.0