[PATCH 5/8] arcnet: com20020-pci: fix dev_id calculation

[Michael Grzeschik]

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.grzesc...@pengutronix.de>
---
 drivers/net/arcnet/com20020-pci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/arcnet/com20020-pci.c 
b/drivers/net/arcnet/com20020-pci.c
index bfbde568e7dc6..47f80b83dcf42 100644
--- a/drivers/net/arcnet/com20020-pci.c
+++ b/drivers/net/arcnet/com20020-pci.c
@@ -135,6 +135,7 @@ static int com20020pci_probe(struct pci_dev *pdev,
        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) {
@@ -180,8 +181,8 @@ static int com20020pci_probe(struct pci_dev *pdev,
 
                /* 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);
 
-- 
2.11.0