[PATCH 18/25] net: stmmac: dwc-qos: Cleanup STMMAC platform data clock pointers

[Serge Semin]

The pointers need to be nullified otherwise the stmmac_remove_config_dt()
method called after them being initialized will disable the clocks. That
then will cause a WARN() backtrace being printed since the clocks would be
also disabled in the locally defined remove method.

Signed-off-by: Serge Semin <sergey.se...@baikalelectronics.ru>
---
 .../stmicro/stmmac/dwmac-dwc-qos-eth.c        | 42 ++++++++++++++-----
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c 
b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
index 2342d497348e..31ca299a1cfd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
@@ -123,39 +123,46 @@ static void *dwc_qos_probe(struct platform_device *pdev,
                           struct plat_stmmacenet_data *plat_dat,
                           struct stmmac_resources *stmmac_res)
 {
+       struct clk *clk;
        int err;
 
-       plat_dat->stmmac_clk = devm_clk_get(&pdev->dev, "apb_pclk");
-       if (IS_ERR(plat_dat->stmmac_clk)) {
+       clk = devm_clk_get(&pdev->dev, "apb_pclk");
+       if (IS_ERR(clk)) {
                dev_err(&pdev->dev, "apb_pclk clock not found.\n");
-               return ERR_CAST(plat_dat->stmmac_clk);
+               return ERR_CAST(clk);
        }
 
-       err = clk_prepare_enable(plat_dat->stmmac_clk);
+       err = clk_prepare_enable(clk);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to enable apb_pclk clock: %d\n",
                        err);
                return ERR_PTR(err);
        }
 
-       plat_dat->pclk = devm_clk_get(&pdev->dev, "phy_ref_clk");
-       if (IS_ERR(plat_dat->pclk)) {
+       plat_dat->stmmac_clk = clk;
+
+       clk = devm_clk_get(&pdev->dev, "phy_ref_clk");
+       if (IS_ERR(clk)) {
                dev_err(&pdev->dev, "phy_ref_clk clock not found.\n");
-               err = PTR_ERR(plat_dat->pclk);
+               err = PTR_ERR(clk);
                goto disable;
        }
 
-       err = clk_prepare_enable(plat_dat->pclk);
+       err = clk_prepare_enable(clk);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to enable phy_ref clock: %d\n",
                        err);
                goto disable;
        }
 
+       plat_dat->pclk = clk;
+
        return NULL;
 
 disable:
        clk_disable_unprepare(plat_dat->stmmac_clk);
+       plat_dat->stmmac_clk = NULL;
+
        return ERR_PTR(err);
 }
 
@@ -164,8 +171,15 @@ static int dwc_qos_remove(struct platform_device *pdev)
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct stmmac_priv *priv = netdev_priv(ndev);
 
+       /* Cleanup the pointers to the clock handlers hidden in the platform
+        * data so the stmmac_remove_config_dt() method wouldn't have disabled
+        * the clocks too.
+        */
        clk_disable_unprepare(priv->plat->pclk);
+       priv->plat->pclk = NULL;
+
        clk_disable_unprepare(priv->plat->stmmac_clk);
+       priv->plat->stmmac_clk = NULL;
 
        return 0;
 }
@@ -303,12 +317,12 @@ static void *tegra_eqos_probe(struct platform_device 
*pdev,
                goto disable_master;
        }
 
-       data->stmmac_clk = eqos->clk_slave;
-
        err = clk_prepare_enable(eqos->clk_slave);
        if (err < 0)
                goto disable_master;
 
+       data->stmmac_clk = eqos->clk_slave;
+
        eqos->clk_rx = devm_clk_get(&pdev->dev, "rx");
        if (IS_ERR(eqos->clk_rx)) {
                err = PTR_ERR(eqos->clk_rx);
@@ -381,6 +395,7 @@ static void *tegra_eqos_probe(struct platform_device *pdev,
        clk_disable_unprepare(eqos->clk_rx);
 disable_slave:
        clk_disable_unprepare(eqos->clk_slave);
+       data->stmmac_clk = NULL;
 disable_master:
        clk_disable_unprepare(eqos->clk_master);
 error:
@@ -390,6 +405,7 @@ static void *tegra_eqos_probe(struct platform_device *pdev,
 
 static int tegra_eqos_remove(struct platform_device *pdev)
 {
+       struct stmmac_priv *priv = netdev_priv(platform_get_drvdata(pdev));
        struct tegra_eqos *eqos = get_stmmac_bsp_priv(&pdev->dev);
 
        reset_control_assert(eqos->rst);
@@ -399,6 +415,12 @@ static int tegra_eqos_remove(struct platform_device *pdev)
        clk_disable_unprepare(eqos->clk_slave);
        clk_disable_unprepare(eqos->clk_master);
 
+       /* Cleanup the pointers to the clock handlers hidden in the platform
+        * data so the stmmac_remove_config_dt() method wouldn't have disabled
+        * the clocks too.
+        */
+       priv->plat->stmmac_clk = NULL;
+
        return 0;
 }
 
-- 
2.29.2