[PATCH] nfc: trf7970a: release runtime PM reference on RF-on errors

[Wentao Liang]

trf7970a_switch_rf_on() bumps the runtime PM usage counter before
validating the state and before initialising the chip.  Neither the
incorrect-state path nor the trf7970a_init() failure path drops that
reference, and none of the three callers balance it either, so the
usage counter stays elevated.

Use pm_runtime_resume_and_get() so that a failed resume does not leave
the counter incremented, and release the reference with the same
mark-last-busy/put-autosuspend pair that trf7970a_switch_rf_off() uses
when either of the subsequent steps fails.

Fixes: e6403b7c756f ("NFC: trf7970a: Add pm_runtime support")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 drivers/nfc/trf7970a.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index ddfc58c29964..7de590485657 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -1150,23 +1150,31 @@ static int trf7970a_switch_rf_on(struct trf7970a *trf)
 
 	dev_dbg(trf->dev, "Switching rf on\n");
 
-	pm_runtime_get_sync(trf->dev);
+	ret = pm_runtime_resume_and_get(trf->dev);
+	if (ret)
+		return ret;
 
 	if (trf->state != TRF7970A_ST_RF_OFF) {	/* Power on, RF off */
 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
 			trf->state);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_put;
 	}
 
 	ret = trf7970a_init(trf);
 	if (ret) {
 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
-		return ret;
+		goto err_put;
 	}
 
 	trf->state = TRF7970A_ST_IDLE;
 
 	return 0;
+
+err_put:
+	pm_runtime_mark_last_busy(trf->dev);
+	pm_runtime_put_autosuspend(trf->dev);
+	return ret;
 }
 
 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
-- 
2.34.1