diff options
| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2012-02-15 17:51:56 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-29 16:31:21 -0800 |
| commit | 9bda01cc81b40639565e63223d7c5413bb15b99a (patch) | |
| tree | 75c55a4f81d57d052e9f8f09faff747dc718765b | |
| parent | c3d65b135f856651b2fa8606a7799a9f33d8f113 (diff) | |
can: sja1000: fix isr hang when hw is unplugged under load
commit a7762b10c12a70c5dbf2253142764b728ac88c3a upstream.
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.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/can/sja1000/sja1000.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index 04a3f1b756a8..192b0d118df4 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -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)) { |