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can: sja1000: fix isr hang when hw is unplugged under load

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In the case of hotplug enabled devices (PCMCIA/PCIeC) the removal of the
hardware can cause an infinite loop in the common sja1000 isr.

Use the already retrieved status register to indicate a possible hardware
removal and double check by reading the mode register in sja1000_is_absent.

Cc: stable@kernel.org [3.2+]
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Oliver Hartkopp 2012-02-15 17:51:56 +01:00 committed by Marc Kleine-Budde
parent 64f0a836f6
commit a7762b10c1
1 changed files with 12 additions and 1 deletions
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13
drivers/net/can/sja1000/sja1000.c
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@ -95,11 +95,16 @@ static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
}
static int sja1000_is_absent(struct sja1000_priv *priv)
{
return (priv->read_reg(priv, REG_MOD) == 0xFF);
}
static int sja1000_probe_chip(struct net_device *dev)
{
struct sja1000_priv *priv = netdev_priv(dev);
if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
if (priv->reg_base && sja1000_is_absent(priv)) {
printk(KERN_INFO "%s: probing @0x%lX failed\n",
DRV_NAME, dev->base_addr);
return 0;
@ -493,6 +498,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
n++;
status = priv->read_reg(priv, REG_SR);
/* check for absent controller due to hw unplug */
if (status == 0xFF && sja1000_is_absent(priv))
return IRQ_NONE;
if (isrc & IRQ_WUI)
dev_warn(dev->dev.parent, "wakeup interrupt\n");
@ -509,6 +517,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
while (status & SR_RBS) {
sja1000_rx(dev);
status = priv->read_reg(priv, REG_SR);
/* check for absent controller */
if (status == 0xFF && sja1000_is_absent(priv))
return IRQ_NONE;
}
}
if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {