[PATCH v2] clk: st: Hold reference returned by of_get_parent()

[PATCH v2] clk: st: Hold reference returned by of_get_parent()

[Liang He]

We should hold the reference returned by of_get_parent() and use it
to call of_node_put() for refcount balance.

Fixes: 3efe64ef5186 ("clk: st: clkgen-fsyn: search reg within node or parent")
Fixes: 810251b0d36a ("clk: st: clkgen-mux: search reg within node or parent")

Signed-off-by: Liang He <windhl@126.com>
---
 changelog:

 v2: replace 'tp' with 'parent_np', change title format to xx:yy:zz
 v1: hold reference returned by of_get_parent()

 v1-link: https://lore.kernel.org/all/20220624104810.4170266-1-windhl@126.com/

 Patched files have been compiled test in 5.19rc2.

 drivers/clk/st/clkgen-fsyn.c | 5 ++++-
 drivers/clk/st/clkgen-mux.c  | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/st/clkgen-fsyn.c b/drivers/clk/st/clkgen-fsyn.c
index 582a22c04919..d820292a381d 100644
--- a/drivers/clk/st/clkgen-fsyn.c
+++ b/drivers/clk/st/clkgen-fsyn.c
@@ -987,6 +987,7 @@ static void __init st_of_quadfs_setup(struct device_node *np,
 	const char *pll_name, *clk_parent_name;
 	void __iomem *reg;
 	spinlock_t *lock;
+	struct device_node *parent_np;
 
 	/*
 	 * First check for reg property within the node to keep backward
@@ -994,7 +995,9 @@ static void __init st_of_quadfs_setup(struct device_node *np,
 	 */
 	reg = of_iomap(np, 0);
 	if (!reg) {
-		reg = of_iomap(of_get_parent(np), 0);
+		parent_np = of_get_parent(np);
+		reg = of_iomap(parent_np, 0);
+		of_node_put(parent_np);
 		if (!reg) {
 			pr_err("%s: Failed to get base address\n", __func__);
 			return;
diff --git a/drivers/clk/st/clkgen-mux.c b/drivers/clk/st/clkgen-mux.c
index ee39af7a0b72..596e939ad905 100644
--- a/drivers/clk/st/clkgen-mux.c
+++ b/drivers/clk/st/clkgen-mux.c
@@ -56,6 +56,7 @@ static void __init st_of_clkgen_mux_setup(struct device_node *np,
 	void __iomem *reg;
 	const char **parents;
 	int num_parents = 0;
+	struct device_node *parent_np;
 
 	/*
 	 * First check for reg property within the node to keep backward
@@ -63,7 +64,9 @@ static void __init st_of_clkgen_mux_setup(struct device_node *np,
 	 */
 	reg = of_iomap(np, 0);
 	if (!reg) {
-		reg = of_iomap(of_get_parent(np), 0);
+		parent_np = of_get_parent(np);
+		reg = of_iomap(parent_np, 0);
+		of_node_put(parent_np);
 		if (!reg) {
 			pr_err("%s: Failed to get base address\n", __func__);
 			return;
-- 
2.25.1

Re: [PATCH v2] clk: st: Hold reference returned by of_get_parent()

[Stephen Boyd]

Quoting Liang He (2022-06-28 07:24:15)
> We should hold the reference returned by of_get_parent() and use it
> to call of_node_put() for refcount balance.
> 
> Fixes: 3efe64ef5186 ("clk: st: clkgen-fsyn: search reg within node or parent")
> Fixes: 810251b0d36a ("clk: st: clkgen-mux: search reg within node or parent")
> 
> Signed-off-by: Liang He <windhl@126.com>
> ---

Applied to clk-next