[PATCH 0/4] mfd: exynos-lpass: Fix some error handling paths

[PATCH 0/4] mfd: exynos-lpass: Fix some error handling paths

[Christophe JAILLET]

This serie fixes several issues related to error handling paths in
drivers/mfd/exynos-lpass.c.

I've split it in 4 patches to ease review, but could be merge in only
1 patch. Or only (3 and 4) could be merged, as they are related.

Patch 1: Fix a leak in the error handling path of the probe. It Should
be straighforward.

Patch 2: Slighly unsure of the order of the code. In the probe, we
enable pm, then lpass, so should we disable lpass, then pm?

Patch 3: Is just a preparation for patch 4. It makes patch 4 more
readable.

Patch 4: Fix a leak in the error handling path of the probe. It Should
be straighforward.


All these patches are compile tested only.

Christophe JAILLET (4):
  mfd: exynos-lpass: Fix an error handling path in exynos_lpass_probe()
  mfd: exynos-lpass: Avoid calling exynos_lpass_disable() twice in
    exynos_lpass_remove()
  mfd: exynos-lpass: Move exynos_lpass_remove()
  mfd: exynos-lpass: Fix another error handling path in
    exynos_lpass_probe()

 drivers/mfd/exynos-lpass.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

-- 
2.49.0

[PATCH 1/4] mfd: exynos-lpass: Fix an error handling path in exynos_lpass_probe()

[Christophe JAILLET]

If an error occurs after a successful regmap_init_mmio(), regmap_exit()
should be called as already done in the .remove() function.

Switch to devm_regmap_init_mmio() to avoid the leak and simplify the
.remove() function.

Fixes: c695abab2429 ("mfd: Add Samsung Exynos Low Power Audio Subsystem driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
The .remove function was added in commit c414df12bdf7 ("mfd: exynos-lpass:
Add missing remove() function")

Compile tested only.
---
 drivers/mfd/exynos-lpass.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
index 6a585173230b..6b95927e99be 100644
--- a/drivers/mfd/exynos-lpass.c
+++ b/drivers/mfd/exynos-lpass.c
@@ -122,8 +122,8 @@ static int exynos_lpass_probe(struct platform_device *pdev)
 	if (IS_ERR(lpass->sfr0_clk))
 		return PTR_ERR(lpass->sfr0_clk);
 
-	lpass->top = regmap_init_mmio(dev, base_top,
-					&exynos_lpass_reg_conf);
+	lpass->top = devm_regmap_init_mmio(dev, base_top,
+					   &exynos_lpass_reg_conf);
 	if (IS_ERR(lpass->top)) {
 		dev_err(dev, "LPASS top regmap initialization failed\n");
 		return PTR_ERR(lpass->top);
@@ -145,7 +145,6 @@ static void exynos_lpass_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		exynos_lpass_disable(lpass);
-	regmap_exit(lpass->top);
 }
 
 static int __maybe_unused exynos_lpass_suspend(struct device *dev)
-- 
2.49.0

Re: [PATCH 1/4] mfd: exynos-lpass: Fix an error handling path in exynos_lpass_probe()

[Krzysztof Kozlowski]

On 29/03/2025 08:45, Christophe JAILLET wrote:
> If an error occurs after a successful regmap_init_mmio(), regmap_exit()
> should be called as already done in the .remove() function.
> 
> Switch to devm_regmap_init_mmio() to avoid the leak and simplify the
> .remove() function.
> 
> Fixes: c695abab2429 ("mfd: Add Samsung Exynos Low Power Audio Subsystem driver")

c414df12bdf7 should be fixed instead, I think.

> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> The .remove function was added in commit c414df12bdf7 ("mfd: exynos-lpass:
> Add missing remove() function")

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 2/4] mfd: exynos-lpass: Avoid calling exynos_lpass_disable() twice in exynos_lpass_remove()

[Christophe JAILLET]

exynos_lpass_disable() is called twice in the remove function. Remove
one of these calls.

Fixes: 90f447170c6f ("mfd: exynos-lpass: Add runtime PM support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only.
---
 drivers/mfd/exynos-lpass.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
index 6b95927e99be..a2785ceea8bf 100644
--- a/drivers/mfd/exynos-lpass.c
+++ b/drivers/mfd/exynos-lpass.c
@@ -141,7 +141,6 @@ static void exynos_lpass_remove(struct platform_device *pdev)
 {
 	struct exynos_lpass *lpass = platform_get_drvdata(pdev);
 
-	exynos_lpass_disable(lpass);
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		exynos_lpass_disable(lpass);
-- 
2.49.0

Re: [PATCH 2/4] mfd: exynos-lpass: Avoid calling exynos_lpass_disable() twice in exynos_lpass_remove()

[Krzysztof Kozlowski]

On 29/03/2025 08:45, Christophe JAILLET wrote:
> exynos_lpass_disable() is called twice in the remove function. Remove
> one of these calls.
> 
> Fixes: 90f447170c6f ("mfd: exynos-lpass: Add runtime PM support")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Compile tested only.
> ---

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 3/4] mfd: exynos-lpass: Move exynos_lpass_remove()

[Christophe JAILLET]

In order be able to call exynos_lpass_remove() from the error handling
path of the probe, it first needs to be moved before the probe.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/mfd/exynos-lpass.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
index a2785ceea8bf..7fd8585ba35a 100644
--- a/drivers/mfd/exynos-lpass.c
+++ b/drivers/mfd/exynos-lpass.c
@@ -104,6 +104,15 @@ static const struct regmap_config exynos_lpass_reg_conf = {
 	.fast_io	= true,
 };
 
+static void exynos_lpass_remove(struct platform_device *pdev)
+{
+	struct exynos_lpass *lpass = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		exynos_lpass_disable(lpass);
+}
+
 static int exynos_lpass_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -137,15 +146,6 @@ static int exynos_lpass_probe(struct platform_device *pdev)
 	return devm_of_platform_populate(dev);
 }
 
-static void exynos_lpass_remove(struct platform_device *pdev)
-{
-	struct exynos_lpass *lpass = platform_get_drvdata(pdev);
-
-	pm_runtime_disable(&pdev->dev);
-	if (!pm_runtime_status_suspended(&pdev->dev))
-		exynos_lpass_disable(lpass);
-}
-
 static int __maybe_unused exynos_lpass_suspend(struct device *dev)
 {
 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
-- 
2.49.0

Re: [PATCH 3/4] mfd: exynos-lpass: Move exynos_lpass_remove()

[Krzysztof Kozlowski]

On 29/03/2025 08:45, Christophe JAILLET wrote:
> In order be able to call exynos_lpass_remove() from the error handling
> path of the probe, it first needs to be moved before the probe.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---

This change makes no sense on its own. There is no point in moving the
code just for moving the code. That's not the goal.

Squash it.

Best regards,
Krzysztof

[PATCH 4/4] mfd: exynos-lpass: Fix another error handling path in exynos_lpass_probe()

[Christophe JAILLET]

If devm_of_platform_populate() fails, some clean-up needs to be done, as
already done in the remove function.

Add the needed error handling path.

Fixes: c695abab2429 ("mfd: Add Samsung Exynos Low Power Audio Subsystem driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only.
---
 drivers/mfd/exynos-lpass.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
index 7fd8585ba35a..9f2601e4e583 100644
--- a/drivers/mfd/exynos-lpass.c
+++ b/drivers/mfd/exynos-lpass.c
@@ -118,6 +118,7 @@ static int exynos_lpass_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct exynos_lpass *lpass;
 	void __iomem *base_top;
+	int ret;
 
 	lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
 	if (!lpass)
@@ -143,7 +144,15 @@ static int exynos_lpass_probe(struct platform_device *pdev)
 	pm_runtime_enable(dev);
 	exynos_lpass_enable(lpass);
 
-	return devm_of_platform_populate(dev);
+	ret = devm_of_platform_populate(dev);
+	if (ret)
+		goto err_remove_exynos_lpass;
+
+	return 0;
+
+err_remove_exynos_lpass:
+	exynos_lpass_remove(pdev);
+	return ret;
 }
 
 static int __maybe_unused exynos_lpass_suspend(struct device *dev)
-- 
2.49.0

Re: [PATCH 4/4] mfd: exynos-lpass: Fix another error handling path in exynos_lpass_probe()

[Krzysztof Kozlowski]

On 29/03/2025 08:45, Christophe JAILLET wrote:
>  	lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
>  	if (!lpass)
> @@ -143,7 +144,15 @@ static int exynos_lpass_probe(struct platform_device *pdev)
>  	pm_runtime_enable(dev);
>  	exynos_lpass_enable(lpass);
>  
> -	return devm_of_platform_populate(dev);
> +	ret = devm_of_platform_populate(dev);
> +	if (ret)
> +		goto err_remove_exynos_lpass;
> +
> +	return 0;
> +
> +err_remove_exynos_lpass:
> +	exynos_lpass_remove(pdev);

You should have here standard unwinding, not calling remove. Or better
just convert everything to devm, because mixing devm and non-devm is
error prone.

Best regards,
Krzysztof