From da875fa5040b0f951cb4bf7efbf59f6dcff44d3c Mon Sep 17 00:00:00 2001
From: Zhang Qilong <zhangqilong3@huawei.com>
Date: Tue, 10 Nov 2020 17:29:33 +0800
Subject: [PATCH] net: fec: Fix reference count leak in fec series ops
Git-commit: da875fa5040b0f951cb4bf7efbf59f6dcff44d3c
Patch-mainline: v5.10-rc5
References: git-fixes

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 count leak. Moreover,
this device cannot enter the idle state and always stay busy or other
non-idle state later. So we fixed it by replacing it with
pm_runtime_resume_and_get.

Fixes: 8fff755e9f8d0 ("net: fec: Ensure clocks are enabled while using mdio bus")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/ethernet/freescale/fec_main.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1769,7 +1769,7 @@ static int fec_enet_mdio_read(struct mii
 	unsigned long time_left;
 	int ret = 0;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
 		return ret;
 
@@ -1806,11 +1806,9 @@ static int fec_enet_mdio_write(struct mi
 	unsigned long time_left;
 	int ret;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
 		return ret;
-	else
-		ret = 0;
 
 	reinit_completion(&fep->mdio_done);
 
@@ -2146,7 +2144,7 @@ static void fec_enet_get_regs(struct net
 	u32 i, off;
 	int ret;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
 		return;
 
@@ -2840,7 +2838,7 @@ fec_enet_open(struct net_device *ndev)
 	int ret;
 	bool reset_again;
 
-	ret = pm_runtime_get_sync(&fep->pdev->dev);
+	ret = pm_runtime_resume_and_get(&fep->pdev->dev);
 	if (ret < 0)
 		return ret;
 
@@ -3591,7 +3589,7 @@ fec_drv_remove(struct platform_device *p
 	struct device_node *np = pdev->dev.of_node;
 	int ret;
 
-	ret = pm_runtime_get_sync(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
 	if (ret < 0)
 		return ret;