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: [email protected] CC: [email protected] Signed-off-by: Wolfgang Zarre <[email protected]> --- drivers/net/can/cc770/cc770_isa.c | 16 +++++++++++++++- 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 4be5fe2..9f3a25c 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) -- 1.7.7.3 _______________________________________________ Socketcan-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-users
