[PATCH 4.14 209/209] net: fec: fix clock count mis-match

Greg Kroah-Hartman
2019-12-04T18:09:39Z

From: Chuhong Yuan <hslester96@gmail.com>

commit a31eda65ba210741b598044d045480494d0ed52a upstream.

pm_runtime_put_autosuspend in probe will call runtime suspend to
disable clks automatically if CONFIG_PM is defined. (If CONFIG_PM
is not defined, its implementation will be empty, then runtime
suspend will not be called.)

Therefore, we can call pm_runtime_get_sync to runtime resume it
first to enable clks, which matches the runtime suspend. (Only when
CONFIG_PM is defined, otherwise pm_runtime_get_sync will also be
empty, then runtime resume will not be called.)

Then it is fine to disable clks without causing clock count mis-match.

Fixes: c43eab3eddb4 ("net: fec: add missed clk_disable_unprepare in remove")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/ethernet/freescale/fec_main.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3565,6 +3565,11 @@ fec_drv_remove(struct platform_device *p
struct net_device *ndev = platform_get_drvdata(pdev);
struct fec_enet_private *fep = netdev_priv(ndev);
struct device_node *np = pdev->dev.of_node;
+ int ret;
+
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0)
+ return ret;

cancel_work_sync(&fep->tx_timeout_work);
fec_ptp_stop(pdev);
@@ -3572,15 +3577,17 @@ fec_drv_remove(struct platform_device *p
fec_enet_mii_remove(fep);
if (fep->reg_phy)
regulator_disable(fep->reg_phy);
- pm_runtime_put(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
- clk_disable_unprepare(fep->clk_ahb);
- clk_disable_unprepare(fep->clk_ipg);
+
if (of_phy_is_fixed_link(np))
of_phy_deregister_fixed_link(np);
of_node_put(fep->phy_node);
free_netdev(ndev);

+ clk_disable_unprepare(fep->clk_ahb);
+ clk_disable_unprepare(fep->clk_ipg);
+ pm_runtime_put_noidle(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
return 0;
}