[PATCH v2] clk: mvebu: ap-cpu: fix missing clk_put() in ap_cpu_clock_probe()

[PATCH v2] clk: mvebu: ap-cpu: fix missing clk_put() in ap_cpu_clock_probe()

[Wentao Liang]

The function ap_cpu_clock_probe() calls of_clk_get() to obtain a
reference to the parent clock for each CPU cluster, but it never
releases it with clk_put().  The returned clk is used only to read
the parent's name via __clk_get_name(), and the reference is leaked
on every successful cluster initialization as well as on the error
path when devm_clk_hw_register() fails.

Rather than adding clk_put() calls, replace the of_clk_get() +
__clk_get_name() pattern with of_clk_get_parent_name(), which is
the intended API for this use case and handles the reference
counting internally.  This matches the pattern already used by the
sibling drivers clk-cpu.c and clk-corediv.c.

Fixes: af9617b419f7 ("clk: mvebu: ap-cpu-clk: Fix a memory leak in error handling paths")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
v2: Replace of_clk_get() + __clk_get_name() with of_clk_get_parent_name()
    as suggested by Brian Masney, instead of adding clk_put() calls.
    Also correct the Fixes: tag to point to the original commit that
    introduced the leak.
---
 drivers/clk/mvebu/ap-cpu-clk.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/clk/mvebu/ap-cpu-clk.c b/drivers/clk/mvebu/ap-cpu-clk.c
index a8175908e353..1cf63c7a0bc3 100644
--- a/drivers/clk/mvebu/ap-cpu-clk.c
+++ b/drivers/clk/mvebu/ap-cpu-clk.c
@@ -288,7 +288,6 @@ static int ap_cpu_clock_probe(struct platform_device *pdev)
 		char *clk_name = "cpu-cluster-0";
 		struct clk_init_data init;
 		const char *parent_name;
-		struct clk *parent;
 		u64 cpu;
 
 		cpu = of_get_cpu_hwid(dn, 0);
@@ -304,13 +303,12 @@ static int ap_cpu_clock_probe(struct platform_device *pdev)
 		if (ap_cpu_data->hws[cluster_index])
 			continue;
 
-		parent = of_clk_get(np, cluster_index);
-		if (IS_ERR(parent)) {
-			dev_err(dev, "Could not get the clock parent\n");
+		parent_name = of_clk_get_parent_name(np, cluster_index);
+		if (!parent_name) {
+			dev_err(dev, "Could not get the clock parent name\n");
 			of_node_put(dn);
 			return -EINVAL;
 		}
-		parent_name =  __clk_get_name(parent);
 		clk_name[12] += cluster_index;
 		ap_cpu_clk[cluster_index].clk_name =
 			ap_cp_unique_name(dev, np->parent, clk_name);
@@ -328,11 +326,9 @@ static int ap_cpu_clock_probe(struct platform_device *pdev)
 		ret = devm_clk_hw_register(dev, &ap_cpu_clk[cluster_index].hw);
 		if (ret) {
 			of_node_put(dn);
-			clk_put(parent);
 			return ret;
 		}
 		ap_cpu_data->hws[cluster_index] = &ap_cpu_clk[cluster_index].hw;
-		clk_put(parent);
 	}
 
 	ap_cpu_data->num = cluster_index + 1;
-- 
2.34.1

Re: [PATCH v2] clk: mvebu: ap-cpu: fix missing clk_put() in ap_cpu_clock_probe()

[Brian Masney]

Hi Wentao,

On Tue, Jun 16, 2026 at 12:29:36PM +0000, Wentao Liang wrote:
> The function ap_cpu_clock_probe() calls of_clk_get() to obtain a
> reference to the parent clock for each CPU cluster, but it never
> releases it with clk_put().  The returned clk is used only to read
> the parent's name via __clk_get_name(), and the reference is leaked
> on every successful cluster initialization as well as on the error
> path when devm_clk_hw_register() fails.
> 
> Rather than adding clk_put() calls, replace the of_clk_get() +
> __clk_get_name() pattern with of_clk_get_parent_name(), which is
> the intended API for this use case and handles the reference
> counting internally.  This matches the pattern already used by the
> sibling drivers clk-cpu.c and clk-corediv.c.
> 
> Fixes: af9617b419f7 ("clk: mvebu: ap-cpu-clk: Fix a memory leak in error handling paths")
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>

The Fixes commit you listed missed this, and yes it should have been
fixed there as well, however the Fixes tag needs to point to the commit
where the leak was first introduced. In this case, it is:

Fixes: f756e362d9384 ("clk: mvebu: add CPU clock driver for Armada 7K/8K")

With that fixed:

Reviewed-by: Brian Masney <bmasney@redhat.com>