[PATCH] pch_gbe: Add NULL check for ptp_pdev in pch_gbe_probe()

[Chenyuan Yang <chenyuan0y@gmail.com>]

Since pci_get_domain_bus_and_slot() can return NULL for PCI_DEVFN(12, 4),
add NULL check for adapter->ptp_pdev in pch_gbe_probe().

This change is similar to the fix implemented in commit 9af152dcf1a0
("drm/gma500: Add NULL check for pci_gfx_root in mid_get_vbt_data()").

Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
---
 drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
index e5a6f59af0b6..10b8f1fea1a2 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
@@ -2515,6 +2515,11 @@ static int pch_gbe_probe(struct pci_dev *pdev,
 		pci_get_domain_bus_and_slot(pci_domain_nr(adapter->pdev->bus),
 					    adapter->pdev->bus->number,
 					    PCI_DEVFN(12, 4));
+	if (!adapter->ptp_pdev) {
+		dev_err(&pdev->dev, "PTP device not found\n");
+		ret = -ENODEV;
+		goto err_free_netdev;
+	}
 
 	netdev->netdev_ops = &pch_gbe_netdev_ops;
 	netdev->watchdog_timeo = PCH_GBE_WATCHDOG_PERIOD;
-- 
2.34.1