[PATCH v2 17/24] net: stmmac: dwc-qos: Cleanup STMMAC platform data clock pointers

Serge Semin
2021-02-08T14:15:27Z

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.Semin@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 27254b27d7ed..20b3696fb776 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 int 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 PTR_ERR(plat_dat->stmmac_clk);
+ return PTR_ERR(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;
}

- 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 0;

disable:
clk_disable_unprepare(plat_dat->stmmac_clk);
+ plat_dat->stmmac_clk = NULL;
+
return 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;
}
@@ -301,12 +315,12 @@ static int 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);
@@ -377,6 +391,7 @@ static int 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:
@@ -385,6 +400,7 @@ static int 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);
@@ -394,6 +410,12 @@ 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