[PATCH 0/3] memory: mtk-smi: fix device leaks on probe

[PATCH 0/3] memory: mtk-smi: fix device leaks on probe

[Johan Hovold]

Make sure to drop the reference taken when looking up the SMI device
during probe on late probe failure (e.g. probe deferral) and on driver
unbind.

Included is also a related cleanup.

Johan


Johan Hovold (3):
  memory: mtk-smi: fix device leaks on common probe
  memory: mtk-smi: fix device leak on larb probe
  memory: mtk-smi: clean up device link creation

 drivers/memory/mtk-smi.c | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

-- 
2.51.2

[PATCH 1/3] memory: mtk-smi: fix device leaks on common probe

[Johan Hovold]

Make sure to drop the reference taken when looking up the SMI device
during common probe on late probe failure (e.g. probe deferral) and on
driver unbind.

Fixes: 47404757702e ("memory: mtk-smi: Add device link for smi-sub-common")
Fixes: 038ae37c510f ("memory: mtk-smi: add missing put_device() call in mtk_smi_device_link_common")
Cc: stable@vger.kernel.org	# 5.16: 038ae37c510f
Cc: Yong Wu <yong.wu@mediatek.com>
Cc: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/memory/mtk-smi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index 733e22f695ab..dd6150d200e8 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -674,6 +674,7 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
 err_pm_disable:
 	pm_runtime_disable(dev);
 	device_link_remove(dev, larb->smi_common_dev);
+	put_device(larb->smi_common_dev);
 	return ret;
 }
 
@@ -917,6 +918,7 @@ static void mtk_smi_common_remove(struct platform_device *pdev)
 	if (common->plat->type == MTK_SMI_GEN2_SUB_COMM)
 		device_link_remove(&pdev->dev, common->smi_common_dev);
 	pm_runtime_disable(&pdev->dev);
+	put_device(common->smi_common_dev);
 }
 
 static int __maybe_unused mtk_smi_common_resume(struct device *dev)
-- 
2.51.2

[PATCH 2/3] memory: mtk-smi: fix device leak on larb probe

[Johan Hovold]

Make sure to drop the reference taken when looking up the SMI device
during larb probe on late probe failure (e.g. probe deferral) and on
driver unbind.

Fixes: cc8bbe1a8312 ("memory: mediatek: Add SMI driver")
Fixes: 038ae37c510f ("memory: mtk-smi: add missing put_device() call in mtk_smi_device_link_common")
Cc: stable@vger.kernel.org	# 4.6: 038ae37c510f
Cc: Yong Wu <yong.wu@mediatek.com>
Cc: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/memory/mtk-smi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index dd6150d200e8..3609bfd3c64b 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -685,6 +685,7 @@ static void mtk_smi_larb_remove(struct platform_device *pdev)
 	device_link_remove(&pdev->dev, larb->smi_common_dev);
 	pm_runtime_disable(&pdev->dev);
 	component_del(&pdev->dev, &mtk_smi_larb_component_ops);
+	put_device(larb->smi_common_dev);
 }
 
 static int __maybe_unused mtk_smi_larb_resume(struct device *dev)
-- 
2.51.2

[PATCH 3/3] memory: mtk-smi: clean up device link creation

[Johan Hovold]

Clean up device link creation by bailing out early in case the SMI
platform device lookup fails.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/memory/mtk-smi.c | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index 3609bfd3c64b..aaeba8ab211e 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -595,25 +595,28 @@ static int mtk_smi_device_link_common(struct device *dev, struct device **com_de
 
 	smi_com_pdev = of_find_device_by_node(smi_com_node);
 	of_node_put(smi_com_node);
-	if (smi_com_pdev) {
-		/* smi common is the supplier, Make sure it is ready before */
-		if (!platform_get_drvdata(smi_com_pdev)) {
-			put_device(&smi_com_pdev->dev);
-			return -EPROBE_DEFER;
-		}
-		smi_com_dev = &smi_com_pdev->dev;
-		link = device_link_add(dev, smi_com_dev,
-				       DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
-		if (!link) {
-			dev_err(dev, "Unable to link smi-common dev\n");
-			put_device(&smi_com_pdev->dev);
-			return -ENODEV;
-		}
-		*com_dev = smi_com_dev;
-	} else {
+	if (!smi_com_pdev) {
 		dev_err(dev, "Failed to get the smi_common device\n");
 		return -EINVAL;
 	}
+
+	/* smi common is the supplier, Make sure it is ready before */
+	if (!platform_get_drvdata(smi_com_pdev)) {
+		put_device(&smi_com_pdev->dev);
+		return -EPROBE_DEFER;
+	}
+
+	smi_com_dev = &smi_com_pdev->dev;
+	link = device_link_add(dev, smi_com_dev,
+			       DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+	if (!link) {
+		dev_err(dev, "Unable to link smi-common dev\n");
+		put_device(&smi_com_pdev->dev);
+		return -ENODEV;
+	}
+
+	*com_dev = smi_com_dev;
+
 	return 0;
 }
 
-- 
2.51.2

Re: [PATCH 1/3] memory: mtk-smi: fix device leaks on common probe

[Krzysztof Kozlowski]

On 21/11/2025 17:46, Johan Hovold wrote:
> Make sure to drop the reference taken when looking up the SMI device
> during common probe on late probe failure (e.g. probe deferral) and on
> driver unbind.
> 
> Fixes: 47404757702e ("memory: mtk-smi: Add device link for smi-sub-common")
> Fixes: 038ae37c510f ("memory: mtk-smi: add missing put_device() call in mtk_smi_device_link_common")
> Cc: stable@vger.kernel.org	# 5.16: 038ae37c510f
> Cc: Yong Wu <yong.wu@mediatek.com>
> Cc: Miaoqian Lin <linmq006@gmail.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>

Thanks Johan.

Side note:
Three weeks and no reviews from Mediatek developers (not necessarily SoC
maintainers, I know your queue is long). So please remember Mediatek: in
case you ever wonder why your patches are waiting on the list for very
long, here is your answer.


Best regards,
Krzysztof

Re: [PATCH 0/3] memory: mtk-smi: fix device leaks on probe

[Krzysztof Kozlowski]

On Fri, 21 Nov 2025 17:46:21 +0100, Johan Hovold wrote:
> Make sure to drop the reference taken when looking up the SMI device
> during probe on late probe failure (e.g. probe deferral) and on driver
> unbind.
> 
> Included is also a related cleanup.
> 
> Johan
> 
> [...]

I fixed up stable-cc syntax - missing final Cc, because only prerequisite was
mentioned.

Applied, thanks!

[1/3] memory: mtk-smi: fix device leaks on common probe
      https://git.kernel.org/krzk/linux-mem-ctrl/c/6cfa038bddd710f544076ea2ef7792fc82fbedd6
[2/3] memory: mtk-smi: fix device leak on larb probe
      https://git.kernel.org/krzk/linux-mem-ctrl/c/9dae65913b32d05dbc8ff4b8a6bf04a0e49a8eb6
[3/3] memory: mtk-smi: clean up device link creation
      https://git.kernel.org/krzk/linux-mem-ctrl/c/78da7027e2a99edea0d7e97b25d75be4698a8728

Best regards,
-- 
Krzysztof Kozlowski <krzk@kernel.org>