[PATCH 3.2 80/92] can: peak_pci: Fix the way channels are linked together

Ben Hutchings
2014-06-07T01:26:29Z

From: Stephane Grosjean <s.grosjean@peak-system.com>

commit 29830406415c227a54af429d7b300aabd4754237 upstream.

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/can/sja1000/peak_pci.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c
index 2c7f503..2147959 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);