From 59d4467be405316916a4087d5b02d99196eeef04 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 1 May 2012 11:49:24 -0700 Subject: w1: introduce a slave mutex for serializing IO w1 devices need a mutex to serial IO. Most use master->mutex. However that is used for other purposes and they can conflict. In particular master->mutex is held while w1_attach_slave_device is called. For bq27000, this registers a 'powersupply' device which tries to read the current status. The attempt to read will cause a deadlock on master->mutex. So create a new per-slave mutex and use that for serializing IO for bq27000. Signed-off-by: NeilBrown Cc: Evgeniy Polyakov Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/w1/slaves/w1_bq27000.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/w1/slaves') diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c index 52ad812fa1e7..87554788fa32 100644 --- a/drivers/w1/slaves/w1_bq27000.c +++ b/drivers/w1/slaves/w1_bq27000.c @@ -31,10 +31,10 @@ static int w1_bq27000_read(struct device *dev, unsigned int reg) u8 val; struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev); - mutex_lock(&sl->master->mutex); + mutex_lock(&sl->mutex); w1_write_8(sl->master, HDQ_CMD_READ | reg); val = w1_read_8(sl->master); - mutex_unlock(&sl->master->mutex); + mutex_unlock(&sl->mutex); return val; } -- cgit v1.2.3-55-g7522