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authorNeilBrown <neilb@suse.de>2012-05-01 11:49:24 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-12 15:27:32 -0700
commit59d4467be405316916a4087d5b02d99196eeef04 (patch)
treec6f42a454b2d3e3818c84bb0050a2f920993b1df /drivers/w1/w1.h
parentbdd4034df8b37841eeaf7b05f86e732ab8e0b08a (diff)
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 <neilb@suse.de> Cc: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/w1.h')
-rw-r--r--drivers/w1/w1.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 4d012ca3f32c..8c8be380a98a 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -75,6 +75,7 @@ struct w1_slave
void *family_data;
struct device dev;
struct completion released;
+ struct mutex mutex;
};
typedef void (*w1_slave_found_callback)(struct w1_master *, u64);