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From:   Qinglang Miao <miaoqinglang@huawei.com>
To:     Michal Simek <michal.simek@xilinx.com>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Qinglang Miao <miaoqinglang@huawei.com>
Subject: [PATCH 1/8] i2c: cadence: fix reference leak when pm_runtime_get_sync fails
Date:   Tue, 1 Dec 2020 17:31:17 +0800
Message-ID: <20201201093117.112900-1-miaoqinglang@huawei.com>
In-Reply-To: <20201201092924.112461-1-miaoqinglang@huawei.com>
References: <20201201092924.112461-1-miaoqinglang@huawei.com>
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The PM reference count is not expected to be incremented on
return in functions cdns_i2c_master_xfer and cdns_reg_slave.

However, pm_runtime_get_sync will increment pm usage counter
even failed. Forgetting to putting operation will result in a
reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced.

Fixes: 7fa32329ca03 ("i2c: cadence: Move to sensible power management")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 drivers/i2c/busses/i2c-cadence.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index e4b7f2a95..e8eae8725 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -789,7 +789,7 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	bool change_role = false;
 #endif
 
-	ret = pm_runtime_get_sync(id->dev);
+	ret = pm_runtime_resume_and_get(id->dev);
 	if (ret < 0)
 		return ret;
 
@@ -911,7 +911,7 @@ static int cdns_reg_slave(struct i2c_client *slave)
 	if (slave->flags & I2C_CLIENT_TEN)
 		return -EAFNOSUPPORT;
 
-	ret = pm_runtime_get_sync(id->dev);
+	ret = pm_runtime_resume_and_get(id->dev);
 	if (ret < 0)
 		return ret;
 
-- 
2.23.0