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From 21c2e3679f5a2068edaf3ae26a8081897f7da66a Mon Sep 17 00:00:00 2001
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Wed, 15 Feb 2012 17:51:56 +0100
Subject: [PATCH 64/72] 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>
---
drivers/net/can/sja1000/sja1000.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 04a3f1b..192b0d1 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)) {
--
1.7.9.4
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