marvell: pxa168_eth: fix call balance of pep->clk handling routines

If the clock pep->clk was not enabled in pxa168_eth_probe,
it should not be disabled in any path.

Conversely, if it was enabled in pxa168_eth_probe, it must be disabled
in all error paths to ensure proper cleanup.

Use the devm_clk_get_enabled helper function to ensure proper call balance
for pep->clk.

Found by Linux Verification Center (linuxtesting.org) with Klever.

Fixes: a49f37eed22b ("net: add Fast Ethernet driver for PXA168.")
Signed-off-by: Vitalii Mordan <mordan@ispras.ru>
Link: https://patch.msgid.link/20241121200658.2203871-1-mordan@ispras.ru
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
index fe38426..2bf426c 100644 (file)
--- a/drivers/net/ethernet/marvell/pxa168_eth.c
+++ b/drivers/net/ethernet/marvell/pxa168_eth.c
@@ -1394,18 +1394,15 @@ static int pxa168_eth_probe(struct platform_device *pdev)
 
        printk(KERN_NOTICE "PXA168 10/100 Ethernet Driver\n");
 
-       clk = devm_clk_get(&pdev->dev, NULL);
+       clk = devm_clk_get_enabled(&pdev->dev, NULL);
        if (IS_ERR(clk)) {
-               dev_err(&pdev->dev, "Fast Ethernet failed to get clock\n");
+               dev_err(&pdev->dev, "Fast Ethernet failed to get and enable clock\n");
                return -ENODEV;
        }
-       clk_prepare_enable(clk);
 
        dev = alloc_etherdev(sizeof(struct pxa168_eth_private));
-       if (!dev) {
-               err = -ENOMEM;
-               goto err_clk;
-       }
+       if (!dev)
+               return -ENOMEM;
 
        platform_set_drvdata(pdev, dev);
        pep = netdev_priv(dev);
@@ -1523,8 +1520,6 @@ err_free_mdio:
        mdiobus_free(pep->smi_bus);
 err_netdev:
        free_netdev(dev);
-err_clk:
-       clk_disable_unprepare(clk);
        return err;
 }
 
@@ -1542,7 +1537,6 @@ static void pxa168_eth_remove(struct platform_device *pdev)
        if (dev->phydev)
                phy_disconnect(dev->phydev);
 
-       clk_disable_unprepare(pep->clk);
        mdiobus_unregister(pep->smi_bus);
        mdiobus_free(pep->smi_bus);
        unregister_netdev(dev);