can: peak_pci: Fix the way channels are linked together

Change the way channels objects are linked together by peak_pci_probe()
avoiding any kernel oops when driver is removed. Side effect is that
the list is now browsed from last to first channel.

Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 9 insertions, 14 deletions

diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c
index 2c7f5036f570..214795945bc4 100644
--- a/drivers/net/can/sja1000/peak_pci.c
+++ b/drivers/net/can/sja1000/peak_pci.c
@@ -39,9 +39,9 @@ MODULE_LICENSE("GPL v2");
 #define DRV_NAME  "peak_pci"
 
 struct peak_pci_chan {
-        void __iomem *cfg_base;      /* Common for all channels */
-        struct net_device *next_dev; /* Chain of network devices */
-        u16 icr_mask;                /* Interrupt mask for fast ack */
+        void __iomem *cfg_base;         /* Common for all channels */
+        struct net_device *prev_dev;    /* Chain of network devices */
+        u16 icr_mask;                   /* Interrupt mask for fast ack */
 };
 
 #define PEAK_PCI_CAN_CLOCK      (16000000 / 2)
@@ -98,7 +98,7 @@ static int __devinit peak_pci_probe(struct pci_dev *pdev,
 {
         struct sja1000_priv *priv;
         struct peak_pci_chan *chan;
-        struct net_device *dev, *dev0 = NULL;
+        struct net_device *dev;
         void __iomem *cfg_base, *reg_base;
         u16 sub_sys_id, icr;
         int i, err, channels;
@@ -196,18 +196,14 @@ static int __devinit peak_pci_probe(struct pci_dev *pdev,
                 }
 
                 /* Create chain of SJA1000 devices */
-                if (i == 0)
-                        dev0 = dev;
-                else
-                        chan->next_dev = dev;
+                chan->prev_dev = pci_get_drvdata(pdev);
+                pci_set_drvdata(pdev, dev);
 
                 dev_info(&pdev->dev,
                          "%s at reg_base=0x%p cfg_base=0x%p irq=%d\n",
                          dev->name, priv->reg_base, chan->cfg_base, dev->irq);
         }
 
-        pci_set_drvdata(pdev, dev0);
-
         /* Enable interrupts */
         writew(icr, cfg_base + PITA_ICR + 2);
 
@@ -217,12 +213,11 @@ failure_remove_channels:
         /* Disable interrupts */
         writew(0x0, cfg_base + PITA_ICR + 2);
 
-        for (dev = dev0; dev; dev = chan->next_dev) {
+        for (dev = pci_get_drvdata(pdev); dev; dev = chan->prev_dev) {
                 unregister_sja1000dev(dev);
                 free_sja1000dev(dev);
                 priv = netdev_priv(dev);
                 chan = priv->priv;
-                dev = chan->next_dev;
         }
 
         pci_iounmap(pdev, reg_base);
@@ -241,7 +236,7 @@ failure_disable_pci:
 
 static void __devexit peak_pci_remove(struct pci_dev *pdev)
 {
-        struct net_device *dev = pci_get_drvdata(pdev); /* First device */
+        struct net_device *dev = pci_get_drvdata(pdev); /* Last device */
         struct sja1000_priv *priv = netdev_priv(dev);
         struct peak_pci_chan *chan = priv->priv;
         void __iomem *cfg_base = chan->cfg_base;
@@ -255,7 +250,7 @@ static void __devexit peak_pci_remove(struct pci_dev *pdev)
                 dev_info(&pdev->dev, "removing device %s\n", dev->name);
                 unregister_sja1000dev(dev);
                 free_sja1000dev(dev);
-                dev = chan->next_dev;
+                dev = chan->prev_dev;
                 if (!dev)
                         break;
                 priv = netdev_priv(dev);