[PATCH] memory: atmel-ebi: release the SMC clock on probe failure

[Wentao Liang]

of_clk_get() returns a consumer reference and clk_prepare_enable()
enables the SMC clock, but the probe error paths after that point
return without dropping either.  If the regmap lookup, the
address/size-cells parsing, disabling a child device or
of_platform_populate() fails, the clock stays enabled and its
reference is leaked.

Unwind both on these error paths.  A successful probe still keeps the
clock enabled for the lifetime of the controller, as before.

Fixes: 87108dc78eb8 ("memory: atmel-ebi: Enable the SMC clock if specified")
Cc: stable at vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab at iscas.ac.cn>
---
 drivers/memory/atmel-ebi.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c
index 1e8e8aba2542..f412e53f4199 100644
--- a/drivers/memory/atmel-ebi.c
+++ b/drivers/memory/atmel-ebi.c
@@ -562,7 +562,7 @@ static int atmel_ebi_probe(struct platform_device *pdev)
 	}
 	ret = clk_prepare_enable(ebi->smc.clk);
 	if (ret)
-		return ret;
+		goto err_clk_put;
 
 	/*
 	 * The sama5d3 does not provide an EBICSA register and thus does need
@@ -572,14 +572,16 @@ static int atmel_ebi_probe(struct platform_device *pdev)
 		ebi->regmap =
 			syscon_regmap_lookup_by_phandle(np,
 							ebi->caps->regmap_name);
-		if (IS_ERR(ebi->regmap))
-			return PTR_ERR(ebi->regmap);
+		if (IS_ERR(ebi->regmap)) {
+			ret = PTR_ERR(ebi->regmap);
+			goto err_clk_disable;
+		}
 	}
 
 	ret = of_property_read_u32(np, "#address-cells", &val);
 	if (ret) {
 		dev_err(dev, "missing #address-cells property\n");
-		return ret;
+		goto err_clk_disable;
 	}
 
 	reg_cells = val;
@@ -587,7 +589,7 @@ static int atmel_ebi_probe(struct platform_device *pdev)
 	ret = of_property_read_u32(np, "#size-cells", &val);
 	if (ret) {
 		dev_err(dev, "missing #address-cells property\n");
-		return ret;
+		goto err_clk_disable;
 	}
 
 	reg_cells += val;
@@ -603,11 +605,22 @@ static int atmel_ebi_probe(struct platform_device *pdev)
 
 			ret = atmel_ebi_dev_disable(ebi, child);
 			if (ret)
-				return ret;
+				goto err_clk_disable;
 		}
 	}
 
-	return of_platform_populate(np, NULL, NULL, dev);
+	ret = of_platform_populate(np, NULL, NULL, dev);
+	if (ret)
+		goto err_clk_disable;
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(ebi->smc.clk);
+err_clk_put:
+	clk_put(ebi->smc.clk);
+
+	return ret;
 }
 
 static __maybe_unused int atmel_ebi_resume(struct device *dev)
-- 
2.34.1