linux-kernel - [PATCH v2] clk: ti: dra7-atl: don't allocate `parent

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Date:   Tue, 18 Oct 2022 18:03:52 +0200
From:   Dario Binacchi <dario.binacchi@...rulasolutions.com>
To:     linux-kernel@...r.kernel.org
Cc:     Amarula patchwork <linux-amarula@...rulasolutions.com>,
        michael@...rulasolutions.com,
        Dario Binacchi <dario.binacchi@...rulasolutions.com>,
        kernel test robot <lkp@...el.com>,
        Allison Randal <allison@...utok.net>,
        Miaoqian Lin <linmq006@...il.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Tero Kristo <kristo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Tony Lindgren <tony@...mide.com>, linux-clk@...r.kernel.org,
        linux-omap@...r.kernel.org
Subject: [PATCH v2] clk: ti: dra7-atl: don't allocate `parent_names' variable

The `parent_names' variable was freed also in case of kzalloc() error.
Instead of modifying the code to perform a proper memory release, I
decided to fix the bug by not allocating memory.
Since only one parent name is referenced, it is not necessary to
allocate this variable at runtime and therefore you can avoid calling
the kzalloc() function. This simplifies the code (even calls to kfree
can be removed) and improves the performance of the routine.

Note: Although no operation is performed by kfree() on a NULL pointer,
it was however suboptimal and semantically wrong doing it.

Signed-off-by: Dario Binacchi <dario.binacchi@...rulasolutions.com>
Reported-by: kernel test robot <lkp@...el.com>

---

Changes in v2:
- Fix compiling error
- Add kernel test robot's Reported-by tag.

 drivers/clk/ti/clk-dra7-atl.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/ti/clk-dra7-atl.c b/drivers/clk/ti/clk-dra7-atl.c
index ff4d6a951681..78482d1a4a33 100644
--- a/drivers/clk/ti/clk-dra7-atl.c
+++ b/drivers/clk/ti/clk-dra7-atl.c
@@ -164,7 +164,7 @@ static void __init of_dra7_atl_clock_setup(struct device_node *node)
 {
 	struct dra7_atl_desc *clk_hw = NULL;
 	struct clk_init_data init = { NULL };
-	const char **parent_names = NULL;
+	const char *parent_names[1];
 	const char *name;
 	struct clk *clk;
 
@@ -188,24 +188,17 @@ static void __init of_dra7_atl_clock_setup(struct device_node *node)
 		goto cleanup;
 	}
 
-	parent_names = kzalloc(sizeof(char *), GFP_KERNEL);
-
-	if (!parent_names)
-		goto cleanup;
-
 	parent_names[0] = of_clk_get_parent_name(node, 0);
 
 	init.parent_names = parent_names;
 
 	clk = ti_clk_register(NULL, &clk_hw->hw, name);
-
 	if (!IS_ERR(clk)) {
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
-		kfree(parent_names);
 		return;
 	}
+
 cleanup:
-	kfree(parent_names);
 	kfree(clk_hw);
 }
 CLK_OF_DECLARE(dra7_atl_clock, "ti,dra7-atl-clock", of_dra7_atl_clock_setup);
-- 
2.32.0