can: xilinx_can: handle failure cases of pm_runtime_get_sync

BugLink: https://bugs.launchpad.net/bugs/1905618
[ Upstream commit 79c43333bdd5a7026a5aab606b53053b643585e7 ]

Calling pm_runtime_get_sync increments the counter even in case of
failure, causing incorrect ref count. Call pm_runtime_put if
pm_runtime_get_sync fails.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Link: https://lore.kernel.org/r/20200605033239.60664-1-navid.emamdoost@gmail.com
Fixes: 4716620d1b62 ("can: xilinx: Convert to runtime_pm")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 2be846ee627d11686493baf74db6c14b6c2dc7c5..0de39ebb356626bc219e0fe304727a1627e257ee 100644 (file)
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -1384,7 +1384,7 @@ static int xcan_open(struct net_device *ndev)
        if (ret < 0) {
                netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
                           __func__, ret);
-               return ret;
+               goto err;
        }
 
        ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
@@ -1468,6 +1468,7 @@ static int xcan_get_berr_counter(const struct net_device *ndev,
        if (ret < 0) {
                netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
                           __func__, ret);
+               pm_runtime_put(priv->dev);
                return ret;
        }
 
@@ -1783,7 +1784,7 @@ static int xcan_probe(struct platform_device *pdev)
        if (ret < 0) {
                netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
                           __func__, ret);
-               goto err_pmdisable;
+               goto err_disableclks;
        }
 
        if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
@@ -1818,7 +1819,6 @@ static int xcan_probe(struct platform_device *pdev)
 
 err_disableclks:
        pm_runtime_put(priv->dev);
-err_pmdisable:
        pm_runtime_disable(&pdev->dev);
 err_free:
        free_candev(ndev);