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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Pavel Machek <pavel@denx.de>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 195/411] Input: stmfts - do not leave device disabled in stmfts_input_open
Date:   Mon, 13 Jun 2022 12:07:48 +0200
Message-Id: <20220613094934.509129154@linuxfoundation.org>
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From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

[ Upstream commit 5f76955ab1e43e5795a9631b22ca4f918a0ae986 ]

The commit 26623eea0da3 attempted to deal with potential leak of runtime
PM counter when opening the touchscreen device, however it ended up
erroneously dropping the counter in the case of successfully enabling the
device.

Let's address this by using pm_runtime_resume_and_get() and then executing
pm_runtime_put_sync() only when we fail to send "sense on" command to the
device.

Fixes: 26623eea0da3 ("Input: stmfts - fix reference leak in stmfts_input_open")
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/input/touchscreen/stmfts.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
index be1dd504d5b1..20bc2279a2f2 100644
--- a/drivers/input/touchscreen/stmfts.c
+++ b/drivers/input/touchscreen/stmfts.c
@@ -337,13 +337,15 @@ static int stmfts_input_open(struct input_dev *dev)
 	struct stmfts_data *sdata = input_get_drvdata(dev);
 	int err;
 
-	err = pm_runtime_get_sync(&sdata->client->dev);
-	if (err < 0)
-		goto out;
+	err = pm_runtime_resume_and_get(&sdata->client->dev);
+	if (err)
+		return err;
 
 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
-	if (err)
-		goto out;
+	if (err) {
+		pm_runtime_put_sync(&sdata->client->dev);
+		return err;
+	}
 
 	mutex_lock(&sdata->mutex);
 	sdata->running = true;
@@ -366,9 +368,7 @@ static int stmfts_input_open(struct input_dev *dev)
 				 "failed to enable touchkey\n");
 	}
 
-out:
-	pm_runtime_put_noidle(&sdata->client->dev);
-	return err;
+	return 0;
 }
 
 static void stmfts_input_close(struct input_dev *dev)
-- 
2.35.1