| Message ID | 20240325184204.745706-2-sboyd@kernel.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | Fix a deadlock with clk_pm_runtime_get() | expand |
Quoting Stephen Boyd (2024-03-25 11:41:55) > Removing this assertion lets us move the kref_put() call outside the > prepare_lock section. We don't need to hold the prepare_lock here to > free memory and destroy the clk_core structure. We've already unlinked > the clk from the clk tree and by the time the release function runs > nothing holds a reference to the clk_core anymore so anything with the > pointer can't access the memory that's being freed anyway. Way back in > commit 496eadf821c2 ("clk: Use lockdep asserts to find missing hold of > prepare_lock") we didn't need to have this assertion either. > > Fixes: 496eadf821c2 ("clk: Use lockdep asserts to find missing hold of prepare_lock") > Cc: Krzysztof Kozlowski <krzk@kernel.org> > Reviewed-by: Douglas Anderson <dianders@chromium.org> > Signed-off-by: Stephen Boyd <sboyd@kernel.org> > --- Applied to clk-fixes
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2253c154a824..44e71736477d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -4353,8 +4353,6 @@ static void __clk_release(struct kref *ref) { struct clk_core *core = container_of(ref, struct clk_core, ref); - lockdep_assert_held(&prepare_lock); - clk_core_free_parent_map(core); kfree_const(core->name); kfree(core);
Removing this assertion lets us move the kref_put() call outside the prepare_lock section. We don't need to hold the prepare_lock here to free memory and destroy the clk_core structure. We've already unlinked the clk from the clk tree and by the time the release function runs nothing holds a reference to the clk_core anymore so anything with the pointer can't access the memory that's being freed anyway. Way back in commit 496eadf821c2 ("clk: Use lockdep asserts to find missing hold of prepare_lock") we didn't need to have this assertion either. Fixes: 496eadf821c2 ("clk: Use lockdep asserts to find missing hold of prepare_lock") Cc: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org> --- drivers/clk/clk.c | 2 -- 1 file changed, 2 deletions(-)