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

Message ID 20170622153110.4079-6-m.grzeschik@pengutronix.de
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Michael Grzeschik June 22, 2017, 3:31 p.m. UTC 
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>
---
 drivers/net/arcnet/com20020-pci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
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Patch

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);