Permit masters to call component_master_add_child() and match the same child multiple times. This may happen if there's multiple connections to a single component device from other devices. In such scenarios, we should not return a failure, but instead ignore the attempt.
Signed-off-by: Russell King rmk+kernel@arm.linux.org.uk --- drivers/base/component.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/base/component.c b/drivers/base/component.c index d0ebd4431736..55813e91bf0d 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -69,6 +69,11 @@ static void component_detach_master(struct master *master, struct component *c) c->master = NULL; }
+/* + * Add a component to a master, finding the component via the compare + * function and compare data. This is safe to call for duplicate matches + * and will not result in the same component being added multiple times. + */ int component_master_add_child(struct master *master, int (*compare)(struct device *, void *), void *compare_data) { @@ -76,11 +81,12 @@ int component_master_add_child(struct master *master, int ret = -ENXIO;
list_for_each_entry(c, &component_list, node) { - if (c->master) + if (c->master && c->master != master) continue;
if (compare(c->dev, compare_data)) { - component_attach_master(master, c); + if (!c->master) + component_attach_master(master, c); ret = 0; break; }