Re: [PATCH net] dwc_eth_qos: do not register semi-initialized device

[David Miller]

From: Lars Persson 
Date: Thu,  8 Sep 2016 13:24:21 +0200

> We move register_netdev() to the end of dwceqos_probe() to close any
> races where the netdev callbacks are called before the initialization
> has finished.
> 
> Reported-by: Pavel Andrianov 
> Signed-off-by: Lars Persson 

Applied.

[PATCH net] dwc_eth_qos: do not register semi-initialized device

[Lars Persson]

We move register_netdev() to the end of dwceqos_probe() to close any
races where the netdev callbacks are called before the initialization
has finished.

Reported-by: Pavel Andrianov 
Signed-off-by: Lars Persson 
---
 drivers/net/ethernet/synopsys/dwc_eth_qos.c | 38 ++---
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/synopsys/dwc_eth_qos.c 
b/drivers/net/ethernet/synopsys/dwc_eth_qos.c
index 5a3941b..4490eba 100644
--- a/drivers/net/ethernet/synopsys/dwc_eth_qos.c
+++ b/drivers/net/ethernet/synopsys/dwc_eth_qos.c
@@ -1246,7 +1246,7 @@ static int dwceqos_mii_init(struct net_local *lp)
lp->mii_bus->read  = _mdio_read;
lp->mii_bus->write = _mdio_write;
lp->mii_bus->priv = lp;
-   lp->mii_bus->parent = >ndev->dev;
+   lp->mii_bus->parent = >pdev->dev;
 
of_address_to_resource(lp->pdev->dev.of_node, 0, );
snprintf(lp->mii_bus->id, MII_BUS_ID_SIZE, "%.8llx",
@@ -2853,25 +2853,17 @@ static int dwceqos_probe(struct platform_device *pdev)
 
ndev->features = ndev->hw_features;
 
-   netif_napi_add(ndev, >napi, dwceqos_rx_poll, NAPI_POLL_WEIGHT);
-
-   ret = register_netdev(ndev);
-   if (ret) {
-   dev_err(>dev, "Cannot register net device, aborting.\n");
-   goto err_out_clk_dis_aper;
-   }
-
lp->phy_ref_clk = devm_clk_get(>dev, "phy_ref_clk");
if (IS_ERR(lp->phy_ref_clk)) {
dev_err(>dev, "phy_ref_clk clock not found.\n");
ret = PTR_ERR(lp->phy_ref_clk);
-   goto err_out_unregister_netdev;
+   goto err_out_clk_dis_aper;
}
 
ret = clk_prepare_enable(lp->phy_ref_clk);
if (ret) {
dev_err(>dev, "Unable to enable device clock.\n");
-   goto err_out_unregister_netdev;
+   goto err_out_clk_dis_aper;
}
 
lp->phy_node = of_parse_phandle(lp->pdev->dev.of_node,
@@ -2880,7 +2872,7 @@ static int dwceqos_probe(struct platform_device *pdev)
ret = of_phy_register_fixed_link(lp->pdev->dev.of_node);
if (ret < 0) {
dev_err(>dev, "invalid fixed-link");
-   goto err_out_unregister_clk_notifier;
+   goto err_out_clk_dis_phy;
}
 
lp->phy_node = of_node_get(lp->pdev->dev.of_node);
@@ -2889,7 +2881,7 @@ static int dwceqos_probe(struct platform_device *pdev)
ret = of_get_phy_mode(lp->pdev->dev.of_node);
if (ret < 0) {
dev_err(>pdev->dev, "error in getting phy i/f\n");
-   goto err_out_unregister_clk_notifier;
+   goto err_out_clk_dis_phy;
}
 
lp->phy_interface = ret;
@@ -2897,14 +2889,14 @@ static int dwceqos_probe(struct platform_device *pdev)
ret = dwceqos_mii_init(lp);
if (ret) {
dev_err(>pdev->dev, "error in dwceqos_mii_init\n");
-   goto err_out_unregister_clk_notifier;
+   goto err_out_clk_dis_phy;
}
 
ret = dwceqos_mii_probe(ndev);
if (ret != 0) {
netdev_err(ndev, "mii_probe fail.\n");
ret = -ENXIO;
-   goto err_out_unregister_clk_notifier;
+   goto err_out_clk_dis_phy;
}
 
dwceqos_set_umac_addr(lp, lp->ndev->dev_addr, 0);
@@ -2922,7 +2914,7 @@ static int dwceqos_probe(struct platform_device *pdev)
if (ret) {
dev_err(>pdev->dev, "Unable to retrieve DT, error %d\n",
ret);
-   goto err_out_unregister_clk_notifier;
+   goto err_out_clk_dis_phy;
}
dev_info(>pdev->dev, "pdev->id %d, baseaddr 0x%08lx, irq %d\n",
 pdev->id, ndev->base_addr, ndev->irq);
@@ -2932,18 +2924,24 @@ static int dwceqos_probe(struct platform_device *pdev)
if (ret) {
dev_err(>pdev->dev, "Unable to request IRQ %d, error %d\n",
ndev->irq, ret);
-   goto err_out_unregister_clk_notifier;
+   goto err_out_clk_dis_phy;
}
 
if (netif_msg_probe(lp))
netdev_dbg(ndev, "net_local@%p\n", lp);
 
+   netif_napi_add(ndev, >napi, dwceqos_rx_poll, NAPI_POLL_WEIGHT);
+
+   ret = register_netdev(ndev);
+   if (ret) {
+   dev_err(>dev, "Cannot register net device, aborting.\n");
+   goto err_out_clk_dis_phy;
+   }
+
return 0;
 
-err_out_unregister_clk_notifier:
+err_out_clk_dis_phy:
clk_disable_unprepare(lp->phy_ref_clk);
-err_out_unregister_netdev:
-   unregister_netdev(ndev);
 err_out_clk_dis_aper:
clk_disable_unprepare(lp->apb_pclk);
 err_out_free_netdev:
-- 
2.1.4