The dev_id was miscalculated. Only the two bits 4-5 are relevant for the
MA1 card. PCIARC1 and PCIFB2 use the four bits 4-7 for id selection.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
        for (i = 0; i < ci->devcount; i++) {
                struct com20020_pci_channel_map *cm = &ci->chan_map_tbl[i];
                struct com20020_dev *card;
+               int dev_id_mask = 0xf;
 
                dev = alloc_arcdev(device);
                if (!dev) {
 
                /* Get the dev_id from the PLX rotary coder */
                if (!strncmp(ci->name, "EAE PLX-PCI MA1", 15))
-                       dev->dev_id = 0xc;
-               dev->dev_id ^= inb(priv->misc + ci->rotary) >> 4;
+                       dev_id_mask = 0x3;
+               dev->dev_id = (inb(priv->misc + ci->rotary) >> 4) & dev_id_mask;
 
                snprintf(dev->name, sizeof(dev->name), "arc%d-%d", dev->dev_id, i);