net: stmmac: Add support for optional reset control

The DWMAC has a reset assert line, which is used on some SoCs. Add an
optional reset control to stmmac driver core.

To support reset control deferred probing, this patch changes the driver
probe function to return the actual error, instead of just -EINVAL.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 37ba2e080825..291608924849 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -100,9 +100,9 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
         stmmac_default_data();
 
         priv = stmmac_dvr_probe(&(pdev->dev), &plat_dat, addr);
-        if (!priv) {
+        if (IS_ERR(priv)) {
                 pr_err("%s: main driver probe failed", __func__);
-                ret = -ENODEV;
+                ret = PTR_ERR(priv);
                 goto err_out;
         }
         priv->dev->irq = pdev->irq;