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/w1.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/w1/w1.c') diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 2f2e894ea0c..69075c3dfc7 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -688,6 +688,7 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); atomic_set(&sl->refcnt, 0); init_completion(&sl->released); + mutex_init(&sl->mutex); spin_lock(&w1_flock); f = w1_family_registered(rn->family); -- cgit v1.2.3-18-g5258