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authorWolfgang Zarre <lkdev@essax.com>2012-01-15 13:21:34 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2012-02-03 00:25:06 +0100
commit2d5091e08c684912ed6b9ca03d1f7b01501b7bf6 (patch)
tree62ae0aca80b9fd4d219e5ab4c7ba5ea37dc6613c /drivers/net/can/cc770
parent7bb4db93ae59e0faf810a83a8578f56bc968ab01 (diff)
can: cc770: Fix indirect access deadlock on ISA cards
This fix avoids a deadlock if an interrupt occurs during consecutive port operations on ISA cards utilising indirect access via address and data port. Tested on a B&R ISA card. Cc: linux-can@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Wolfgang Zarre <lkdev@essax.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/cc770')
-rw-r--r--drivers/net/can/cc770/cc770_isa.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/net/can/cc770/cc770_isa.c b/drivers/net/can/cc770/cc770_isa.c
index 4be5fe2c40a..9f3a25ccd66 100644
--- a/drivers/net/can/cc770/cc770_isa.c
+++ b/drivers/net/can/cc770/cc770_isa.c
@@ -110,6 +110,11 @@ MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
#define CC770_IOSIZE 0x20
#define CC770_IOSIZE_INDIRECT 0x02
+/* Spinlock for cc770_isa_port_write_reg_indirect
+ * and cc770_isa_port_read_reg_indirect
+ */
+static DEFINE_SPINLOCK(cc770_isa_port_lock);
+
static struct platform_device *cc770_isa_devs[MAXDEV];
static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
@@ -138,18 +143,27 @@ static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
int reg)
{
unsigned long base = (unsigned long)priv->reg_base;
+ unsigned long flags;
+ u8 val;
+ spin_lock_irqsave(&cc770_isa_port_lock, flags);
outb(reg, base);
- return inb(base + 1);
+ val = inb(base + 1);
+ spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
+
+ return val;
}
static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
int reg, u8 val)
{
unsigned long base = (unsigned long)priv->reg_base;
+ unsigned long flags;
+ spin_lock_irqsave(&cc770_isa_port_lock, flags);
outb(reg, base);
outb(val, base + 1);
+ spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
}
static int __devinit cc770_isa_probe(struct platform_device *pdev)