arcnet: com20020-pci: handle backplane mode depending on card type

We read the backplane mode of each subcard from bits 2 and 3 of the misc
register.
Signed-off-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/arcnet/com20020-pci.c

@@ -199,6 +199,8 @@ static int com20020pci_probe(struct pci_dev *pdev,
 		lp->timeout = timeout;
 		lp->hw.owner = THIS_MODULE;
 
+		lp->backplane = (inb(priv->misc) >> (2 + i)) & 0x1;
+
 		/* Get the dev_id from the PLX rotary coder */
 		if (!strncmp(ci->name, "EAE PLX-PCI MA1", 15))
 			dev->dev_id = 0xc;