[PATCH] lockdep: annotate sound/core/seq/seq_device.c

The ops structure has complex locking rules, where not all ops are equal, some
are subordinate on others for some complex sound cards.  This requires for
lockdep checking that each individual reg_mutex is considered in separation
for its locking rules.

Has no effect on non-lockdep kernels.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jaroslav Kysela <perex@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/sound/core/seq/seq_device.c b/sound/core/seq/seq_device.c
index d812dc886360286ff2e609efe7e1850145bd646e..4260de90f36fb39468d7a623649f7f7486a4ab9c 100644 (file)
--- a/sound/core/seq/seq_device.c
+++ b/sound/core/seq/seq_device.c
@@ -380,6 +380,12 @@ static struct ops_list * create_driver(char *id)
        /* set up driver entry */
        strlcpy(ops->id, id, sizeof(ops->id));
        mutex_init(&ops->reg_mutex);
+       /*
+        * The ->reg_mutex locking rules are per-driver, so we create
+        * separate per-driver lock classes:
+        */
+       lockdep_set_class(&ops->reg_mutex, (struct lock_class_key *)id);
+
        ops->driver = DRIVER_EMPTY;
        INIT_LIST_HEAD(&ops->dev_list);
        /* lock this instance */