From: Zhang Qilong <zhangqilong3@huawei.com>
Date: Sun, 8 Nov 2020 16:30:00 +0800
Subject: can: flexcan: fix failure handling of pm_runtime_get_sync()

Git-commit: b7ee5bc3e1006433601a058a6a7c24c5272635f4
Patch-mainline: v5.10-rc5
References: jsc#SLE-12251

pm_runtime_get_sync() will increment pm usage at first and it will resume the
device later. If runtime of the device has error or device is in inaccessible
state(or other error state), resume operation will fail. If we do not call put
operation to decrease the reference, it will result in reference leak in the
two functions flexcan_get_berr_counter() and flexcan_open().

Moreover, this device cannot enter the idle state and always stay busy or other
non-idle state later. So we should fix it through adding
pm_runtime_put_noidle().

Fixes: ca10989632d88 ("can: flexcan: implement can Runtime PM")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201108083000.2599705-1-zhangqilong3@huawei.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/net/can/flexcan.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 4e8fdb6064bd..d6a9cf0e9b60 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -728,8 +728,10 @@ static int flexcan_get_berr_counter(const struct net_device *dev,
 	int err;
 
 	err = pm_runtime_get_sync(priv->dev);
-	if (err < 0)
+	if (err < 0) {
+		pm_runtime_put_noidle(priv->dev);
 		return err;
+	}
 
 	err = __flexcan_get_berr_counter(dev, bec);
 
@@ -1654,8 +1656,10 @@ static int flexcan_open(struct net_device *dev)
 	}
 
 	err = pm_runtime_get_sync(priv->dev);
-	if (err < 0)
+	if (err < 0) {
+		pm_runtime_put_noidle(priv->dev);
 		return err;
+	}
 
 	err = open_candev(dev);
 	if (err)
-- 
2.26.2