linux-kernel - [PATCH 1/5] clk: Remove prepare_lock hold assertion in __clk

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Date: Sun, 24 Mar 2024 22:43:58 -0700
From: Stephen Boyd <sboyd@...nel.org>
To: Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>
Cc: linux-kernel@...r.kernel.org,
	linux-clk@...r.kernel.org,
	patches@...ts.linux.dev,
	linux-arm-msm@...r.kernel.org,
	Krzysztof Kozlowski <krzk@...nel.org>,
	Douglas Anderson <dianders@...omium.org>
Subject: [PATCH 1/5] clk: Remove prepare_lock hold assertion in __clk_release()

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@...nel.org>
Cc: Douglas Anderson <dianders@...omium.org>
Signed-off-by: Stephen Boyd <sboyd@...nel.org>
---
 drivers/clk/clk.c | 2 --
 1 file changed, 2 deletions(-)

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);
-- 
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git