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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Stephen Boyd <sboyd@kernel.org>,
	Douglas Anderson <dianders@chromium.org>,
	Sasha Levin <sashal@kernel.org>,
	mturquette@baylibre.com,
	linux-clk@vger.kernel.org
Subject: [PATCH AUTOSEL 5.15 6/9] clk: Don't hold prepare_lock when calling kref_put()
Date: Tue, 23 Apr 2024 07:02:28 -0400
Message-ID: <20240423110233.1659071-6-sashal@kernel.org>
In-Reply-To: <20240423110233.1659071-1-sashal@kernel.org>
References: <20240423110233.1659071-1-sashal@kernel.org>
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From: Stephen Boyd <sboyd@kernel.org>

[ Upstream commit 6f63af7511e7058f3fa4ad5b8102210741c9f947 ]

We don't need to hold the prepare_lock when dropping a ref on a struct
clk_core. The release function is only freeing memory and any code with
a pointer reference has already unlinked anything pointing to the
clk_core. This reduces the holding area of the prepare_lock a bit.

Note that we also don't call free_clk() with the prepare_lock held.
There isn't any reason to do that.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240325184204.745706-3-sboyd@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clk/clk.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 84397af4fb336..7a3b992ca3e40 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4137,7 +4137,8 @@ void clk_unregister(struct clk *clk)
 	if (ops == &clk_nodrv_ops) {
 		pr_err("%s: unregistered clock: %s\n", __func__,
 		       clk->core->name);
-		goto unlock;
+		clk_prepare_unlock();
+		return;
 	}
 	/*
 	 * Assign empty clock ops for consumers that might still hold
@@ -4171,11 +4172,10 @@ void clk_unregister(struct clk *clk)
 	if (clk->core->protect_count)
 		pr_warn("%s: unregistering protected clock: %s\n",
 					__func__, clk->core->name);
+	clk_prepare_unlock();
 
 	kref_put(&clk->core->ref, __clk_release);
 	free_clk(clk);
-unlock:
-	clk_prepare_unlock();
 }
 EXPORT_SYMBOL_GPL(clk_unregister);
 
@@ -4381,13 +4381,11 @@ void __clk_put(struct clk *clk)
 	    clk->max_rate < clk->core->req_rate)
 		clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
 
-	owner = clk->core->owner;
-	kref_put(&clk->core->ref, __clk_release);
-
 	clk_prepare_unlock();
 
+	owner = clk->core->owner;
+	kref_put(&clk->core->ref, __clk_release);
 	module_put(owner);
-
 	free_clk(clk);
 }
 
-- 
2.43.0