[PATCH] iio: gyro: mpu3050: Fix runtime PM leak on trigger errors

[Ruoyu Wang <ruoyuw560@gmail.com>]

The first user of the MPU-3050 data-ready trigger takes a runtime PM
reference before configuring the FIFO, sample engine and interrupt. If
any of those operations fails, iio_trigger_attach_poll_func() tears down
its IRQ resources without calling set_trigger_state(false). The buffer
error path then releases only its preenable reference, leaving the
trigger's reference held and preventing runtime suspend.

Use pm_runtime_resume_and_get() so a resume failure does not leave a
usage count behind. Route later setup failures through a common unwind
that clears hw_irq_trigger and drops the trigger's reference. Successful
enable and disable behavior is unchanged.

This issue was found by a static analysis checker and confirmed by
manual source review.

Fixes: f11d59d87b8622 ("iio: Move attach/detach of the poll func to the core")
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
---
 drivers/iio/gyro/mpu3050-core.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
index d84e04e4b4314..33a98a6e9cb84 100644
--- a/drivers/iio/gyro/mpu3050-core.c
+++ b/drivers/iio/gyro/mpu3050-core.c
@@ -988,20 +988,23 @@ static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
 		return 0;
 	} else {
 		/* Else we're enabling the trigger from this point */
-		pm_runtime_get_sync(mpu3050->dev);
+		ret = pm_runtime_resume_and_get(mpu3050->dev);
+		if (ret)
+			return ret;
+
 		mpu3050->hw_irq_trigger = true;
 
 		/* Disable all things in the FIFO */
 		ret = regmap_write(mpu3050->map, MPU3050_FIFO_EN, 0);
 		if (ret)
-			return ret;
+			goto err_pm_put;
 
 		/* Reset and enable the FIFO */
 		ret = regmap_set_bits(mpu3050->map, MPU3050_USR_CTRL,
 				      MPU3050_USR_CTRL_FIFO_EN |
 				      MPU3050_USR_CTRL_FIFO_RST);
 		if (ret)
-			return ret;
+			goto err_pm_put;
 
 		mpu3050->pending_fifo_footer = false;
 
@@ -1013,12 +1016,12 @@ static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
 				   MPU3050_FIFO_EN_GYRO_ZOUT |
 				   MPU3050_FIFO_EN_FOOTER);
 		if (ret)
-			return ret;
+			goto err_pm_put;
 
 		/* Configure the sample engine */
 		ret = mpu3050_start_sampling(mpu3050);
 		if (ret)
-			return ret;
+			goto err_pm_put;
 
 		/* Clear IRQ flag */
 		ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
@@ -1037,10 +1040,16 @@ static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
 
 		ret = regmap_write(mpu3050->map, MPU3050_INT_CFG, val);
 		if (ret)
-			return ret;
+			goto err_pm_put;
 	}
 
 	return 0;
+
+err_pm_put:
+	mpu3050->hw_irq_trigger = false;
+	pm_runtime_put_autosuspend(mpu3050->dev);
+
+	return ret;
 }
 
 static const struct iio_trigger_ops mpu3050_trigger_ops = {
-- 
2.51.0