linux-kernel - [PATCH v3 2/2] clk: ti: dra7-atl: don't allocate `parent

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Date:   Sun,  6 Nov 2022 16:46:12 +0100
From:   Dario Binacchi <dario.binacchi@...rulasolutions.com>
To:     linux-kernel@...r.kernel.org
Cc:     michael@...rulasolutions.com,
        Amarula patchwork <linux-amarula@...rulasolutions.com>,
        Dario Binacchi <dario.binacchi@...rulasolutions.com>,
        kernel test robot <lkp@...el.com>,
        Allison Randal <allison@...utok.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        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 v3 2/2] 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.

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

---

Changes in v3:
- Add the "clk: ti: add of_ti_clk_register() helper" patch to the series.
- Use a variable of type struct clk_parent_data to furthermore simplify
  the code.
- Update the commit message.

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

 drivers/clk/ti/clk-dra7-atl.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/ti/clk-dra7-atl.c b/drivers/clk/ti/clk-dra7-atl.c
index ff4d6a951681..373561626ec4 100644
--- a/drivers/clk/ti/clk-dra7-atl.c
+++ b/drivers/clk/ti/clk-dra7-atl.c
@@ -163,8 +163,8 @@ static const struct clk_ops atl_clk_ops = {
 static void __init of_dra7_atl_clock_setup(struct device_node *node)
 {
 	struct dra7_atl_desc *clk_hw = NULL;
+	struct clk_parent_data pdata = { .index = 0 };
 	struct clk_init_data init = { NULL };
-	const char **parent_names = NULL;
 	const char *name;
 	struct clk *clk;
 
@@ -188,24 +188,15 @@ 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);
+	init.parent_data = &pdata;
 
+	clk = of_ti_clk_register(node, &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