Assign module owner of a driver of a device passed to _clk_register()
and __clk_register() functions so the module_{get,put} calls in
__clk_get(), __clk_put() can have required effect.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
Initially I had an 'owner' field added to struct clk_init_data so it can
be set explicitly in clock providers. But this required modifications
of all users of (devm_)clk_register() as struct clk_init_data instance
was in most cases an unitialized stack variable. This would also require
adding yet another argument to various clk_register_* functions
registering the standard clocks. So I went for assigning clk->owner from
dev->driver->owner. The disadvantages are that dereferencing dev->driver
may be potentially unsafe when not holding struct device::mutex. And
there might be cases where clk->owner will need to be NULL. One option
is to set dev argument of clk_register_*() to NULL for that, but it
predates devm_*.
Presumably a requirement could be added that callers of clk_register*()
must ensure dev->driver won't change during a call to these functions ?
---
drivers/clk/clk.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index c173f30..272d68d 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1692,6 +1692,10 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
clk->flags = hw->init->flags;
clk->parent_names = hw->init->parent_names;
clk->num_parents = hw->init->num_parents;
+ if (dev && dev->driver)
+ clk->owner = dev->driver->owner;
+ else
+ clk->owner = NULL;
ret = __clk_init(dev, clk);
if (ret)
@@ -1712,6 +1716,8 @@ static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
goto fail_name;
}
clk->ops = hw->init->ops;
+ if (dev && dev->driver)
+ clk->owner = dev->driver->owner;
clk->hw = hw;
clk->flags = hw->init->flags;
clk->num_parents = hw->init->num_parents;
--
1.7.9.5
