bnxt_en: Fix PCI AER error recovery flow

[ Upstream commit df3875ec ]

When a PCI error is detected the PCI state could be corrupt, save
the PCI state after initialization and restore it after the slot
reset.

Fixes: 6316ea6d ("bnxt_en: Enable AER support.")
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -9128,6 +9128,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		    (long)pci_resource_start(pdev, 0), dev->dev_addr);
 	pcie_print_link_status(pdev);
 
+	pci_save_state(pdev);
 	return 0;
 
 init_err_cleanup_tc:
@@ -9289,6 +9290,8 @@ static pci_ers_result_t bnxt_io_slot_reset(struct pci_dev *pdev)
 			"Cannot re-enable PCI device after reset.\n");
 	} else {
 		pci_set_master(pdev);
+		pci_restore_state(pdev);
+		pci_save_state(pdev);
 
 		err = bnxt_hwrm_func_reset(bp);
 		if (!err && netif_running(netdev))