[PATCH] soc: imx8m: Add remove function

[PATCH] soc: imx8m: Add remove function

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@nxp.com>

Unregister the cpufreq device and soc device in remove path, otherwise
there will be warning when do removing test:
sysfs: cannot create duplicate filename '/devices/platform/imx-cpufreq-dt'
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.13.0-rc1-next-20241204
Hardware name: NXP i.MX8MPlus EVK board (DT)

Fixes: 9cc832d37799 ("soc: imx8m: Probe the SoC driver as platform driver")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/soc/imx/soc-imx8m.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index 8ac7658e3d52..8c368947d1e5 100644
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -33,6 +33,11 @@ struct imx8_soc_data {
 	int (*soc_revision)(u32 *socrev, u64 *socuid);
 };
 
+struct imx8m_soc_priv {
+	struct soc_device *soc_dev;
+	struct platform_device *cpufreq_dev;
+};
+
 #ifdef CONFIG_HAVE_ARM_SMCCC
 static u32 imx8mq_soc_revision_from_atf(void)
 {
@@ -198,7 +203,7 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 	const struct imx8_soc_data *data;
 	struct device *dev = &pdev->dev;
 	const struct of_device_id *id;
-	struct soc_device *soc_dev;
+	struct imx8m_soc_priv *priv;
 	u32 soc_rev = 0;
 	u64 soc_uid = 0;
 	int ret;
@@ -207,6 +212,10 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 	if (!soc_dev_attr)
 		return -ENOMEM;
 
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
 	soc_dev_attr->family = "Freescale i.MX";
 
 	ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
@@ -235,21 +244,34 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 	if (!soc_dev_attr->serial_number)
 		return -ENOMEM;
 
-	soc_dev = soc_device_register(soc_dev_attr);
-	if (IS_ERR(soc_dev))
-		return PTR_ERR(soc_dev);
+	priv->soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(priv->soc_dev))
+		return PTR_ERR(priv->soc_dev);
 
 	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
 		soc_dev_attr->revision);
 
 	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
-		platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
+		priv->cpufreq_dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
+
+	platform_set_drvdata(pdev, priv);
 
 	return 0;
 }
 
+static void imx8m_soc_remove(struct platform_device *pdev)
+{
+	struct imx8m_soc_priv *priv = platform_get_drvdata(pdev);
+
+	if (!IS_ERR(priv->cpufreq_dev))
+		platform_device_unregister(priv->cpufreq_dev);
+
+	soc_device_unregister(priv->soc_dev);
+}
+
 static struct platform_driver imx8m_soc_driver = {
 	.probe = imx8m_soc_probe,
+	.remove	= imx8m_soc_remove,
 	.driver = {
 		.name = "imx8m-soc",
 	},
-- 
2.37.1

Re: [PATCH] soc: imx8m: Add remove function

[Marco Felsch]

On 24-12-06, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> Unregister the cpufreq device and soc device in remove path, otherwise
> there will be warning when do removing test:
> sysfs: cannot create duplicate filename '/devices/platform/imx-cpufreq-dt'
> CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.13.0-rc1-next-20241204
> Hardware name: NXP i.MX8MPlus EVK board (DT)
> 
> Fixes: 9cc832d37799 ("soc: imx8m: Probe the SoC driver as platform driver")
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/soc/imx/soc-imx8m.c | 32 +++++++++++++++++++++++++++-----
>  1 file changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
> index 8ac7658e3d52..8c368947d1e5 100644
> --- a/drivers/soc/imx/soc-imx8m.c
> +++ b/drivers/soc/imx/soc-imx8m.c
> @@ -33,6 +33,11 @@ struct imx8_soc_data {
>  	int (*soc_revision)(u32 *socrev, u64 *socuid);
>  };
>  
> +struct imx8m_soc_priv {
> +	struct soc_device *soc_dev;
> +	struct platform_device *cpufreq_dev;
> +};
> +
>  #ifdef CONFIG_HAVE_ARM_SMCCC
>  static u32 imx8mq_soc_revision_from_atf(void)
>  {
> @@ -198,7 +203,7 @@ static int imx8m_soc_probe(struct platform_device *pdev)
>  	const struct imx8_soc_data *data;
>  	struct device *dev = &pdev->dev;
>  	const struct of_device_id *id;
> -	struct soc_device *soc_dev;
> +	struct imx8m_soc_priv *priv;
>  	u32 soc_rev = 0;
>  	u64 soc_uid = 0;
>  	int ret;
> @@ -207,6 +212,10 @@ static int imx8m_soc_probe(struct platform_device *pdev)
>  	if (!soc_dev_attr)
>  		return -ENOMEM;
>  
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
>  	soc_dev_attr->family = "Freescale i.MX";
>  
>  	ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
> @@ -235,21 +244,34 @@ static int imx8m_soc_probe(struct platform_device *pdev)
>  	if (!soc_dev_attr->serial_number)
>  		return -ENOMEM;
>  
> -	soc_dev = soc_device_register(soc_dev_attr);
> -	if (IS_ERR(soc_dev))
> -		return PTR_ERR(soc_dev);
> +	priv->soc_dev = soc_device_register(soc_dev_attr);
> +	if (IS_ERR(priv->soc_dev))
> +		return PTR_ERR(priv->soc_dev);
>  
>  	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
>  		soc_dev_attr->revision);
>  
>  	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> -		platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> +		priv->cpufreq_dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);

If CONFIG_ARM_IMX_CPUFREQ_DT is enabled, I asusme that
platform_device_register_simple() shouldn't fail else it will be an
error, right? Therefore I would like to add the 'if(!IS_ERR())' check
here instead of the remove function.

> +
> +	platform_set_drvdata(pdev, priv);
>  
>  	return 0;
>  }
>  
> +static void imx8m_soc_remove(struct platform_device *pdev)
> +{
> +	struct imx8m_soc_priv *priv = platform_get_drvdata(pdev);
> +
> +	if (!IS_ERR(priv->cpufreq_dev))

With the above shifted, we only need to:
	if (priv->cpufreq_dev)

Regards,
  Marco


> +		platform_device_unregister(priv->cpufreq_dev);
> +
> +	soc_device_unregister(priv->soc_dev);
> +}
> +
>  static struct platform_driver imx8m_soc_driver = {
>  	.probe = imx8m_soc_probe,
> +	.remove	= imx8m_soc_remove,
>  	.driver = {
>  		.name = "imx8m-soc",
>  	},
> -- 
> 2.37.1
> 
> 
> 

RE: [PATCH] soc: imx8m: Add remove function

[Peng Fan]

> Subject: Re: [PATCH] soc: imx8m: Add remove function
> 
> On 24-12-06, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > Unregister the cpufreq device and soc device in remove path,
> otherwise
> > there will be warning when do removing test:
> > sysfs: cannot create duplicate filename '/devices/platform/imx-
> cpufreq-dt'
> > CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted
> > 6.13.0-rc1-next-20241204 Hardware name: NXP i.MX8MPlus EVK
> board (DT)
> >
> > Fixes: 9cc832d37799 ("soc: imx8m: Probe the SoC driver as platform
> > driver")
> > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > ---
> >  drivers/soc/imx/soc-imx8m.c | 32 +++++++++++++++++++++++++++----
> -
> >  1 file changed, 27 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-
> imx8m.c
> > index 8ac7658e3d52..8c368947d1e5 100644
> > --- a/drivers/soc/imx/soc-imx8m.c
> > +++ b/drivers/soc/imx/soc-imx8m.c
> > @@ -33,6 +33,11 @@ struct imx8_soc_data {
> >  	int (*soc_revision)(u32 *socrev, u64 *socuid);  };
> >
> > +struct imx8m_soc_priv {
> > +	struct soc_device *soc_dev;
> > +	struct platform_device *cpufreq_dev; };
> > +
> >  #ifdef CONFIG_HAVE_ARM_SMCCC
> >  static u32 imx8mq_soc_revision_from_atf(void)
> >  {
> > @@ -198,7 +203,7 @@ static int imx8m_soc_probe(struct
> platform_device *pdev)
> >  	const struct imx8_soc_data *data;
> >  	struct device *dev = &pdev->dev;
> >  	const struct of_device_id *id;
> > -	struct soc_device *soc_dev;
> > +	struct imx8m_soc_priv *priv;
> >  	u32 soc_rev = 0;
> >  	u64 soc_uid = 0;
> >  	int ret;
> > @@ -207,6 +212,10 @@ static int imx8m_soc_probe(struct
> platform_device *pdev)
> >  	if (!soc_dev_attr)
> >  		return -ENOMEM;
> >
> > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +	if (!priv)
> > +		return -ENOMEM;
> > +
> >  	soc_dev_attr->family = "Freescale i.MX";
> >
> >  	ret = of_property_read_string(of_root, "model",
> > &soc_dev_attr->machine); @@ -235,21 +244,34 @@ static int
> imx8m_soc_probe(struct platform_device *pdev)
> >  	if (!soc_dev_attr->serial_number)
> >  		return -ENOMEM;
> >
> > -	soc_dev = soc_device_register(soc_dev_attr);
> > -	if (IS_ERR(soc_dev))
> > -		return PTR_ERR(soc_dev);
> > +	priv->soc_dev = soc_device_register(soc_dev_attr);
> > +	if (IS_ERR(priv->soc_dev))
> > +		return PTR_ERR(priv->soc_dev);
> >
> >  	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
> >  		soc_dev_attr->revision);
> >
> >  	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> > -		platform_device_register_simple("imx-cpufreq-dt", -1,
> NULL, 0);
> > +		priv->cpufreq_dev =
> > +platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> 
> If CONFIG_ARM_IMX_CPUFREQ_DT is enabled, I asusme that
> platform_device_register_simple() shouldn't fail else it will be an error,
> right? Therefore I would like to add the 'if(!IS_ERR())' check here
> instead of the remove function.

You mean below?
dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
if (!IS_ERR(dev))
   plat->cpufreq_dev = dev;
else
  pr_err("Failed to register imx-cpufreq-dt: %d\n", ERR_PTR(dev))?

But using !IS_ERR(plat->cpufreq_dev) in remove path looks
simpler.

Thanks,
Peng

> 
> > +
> > +	platform_set_drvdata(pdev, priv);
> >
> >  	return 0;
> >  }
> >
> > +static void imx8m_soc_remove(struct platform_device *pdev) {
> > +	struct imx8m_soc_priv *priv = platform_get_drvdata(pdev);
> > +
> > +	if (!IS_ERR(priv->cpufreq_dev))
> 
> With the above shifted, we only need to:
> 	if (priv->cpufreq_dev)
> 
> Regards,
>   Marco
> 
> 
> > +		platform_device_unregister(priv->cpufreq_dev);
> > +
> > +	soc_device_unregister(priv->soc_dev);
> > +}
> > +
> >  static struct platform_driver imx8m_soc_driver = {
> >  	.probe = imx8m_soc_probe,
> > +	.remove	= imx8m_soc_remove,
> >  	.driver = {
> >  		.name = "imx8m-soc",
> >  	},
> > --
> > 2.37.1
> >
> >
> >

Re: [PATCH] soc: imx8m: Add remove function

[Shawn Guo]

On Mon, Dec 09, 2024 at 08:26:48AM +0000, Peng Fan wrote:
> > Subject: Re: [PATCH] soc: imx8m: Add remove function
> > 
> > On 24-12-06, Peng Fan (OSS) wrote:
> > > From: Peng Fan <peng.fan@nxp.com>
> > >
> > > Unregister the cpufreq device and soc device in remove path,
> > otherwise
> > > there will be warning when do removing test:
> > > sysfs: cannot create duplicate filename '/devices/platform/imx-
> > cpufreq-dt'
> > > CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted
> > > 6.13.0-rc1-next-20241204 Hardware name: NXP i.MX8MPlus EVK
> > board (DT)
> > >
> > > Fixes: 9cc832d37799 ("soc: imx8m: Probe the SoC driver as platform
> > > driver")
> > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >  drivers/soc/imx/soc-imx8m.c | 32 +++++++++++++++++++++++++++----
> > -
> > >  1 file changed, 27 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-
> > imx8m.c
> > > index 8ac7658e3d52..8c368947d1e5 100644
> > > --- a/drivers/soc/imx/soc-imx8m.c
> > > +++ b/drivers/soc/imx/soc-imx8m.c
> > > @@ -33,6 +33,11 @@ struct imx8_soc_data {
> > >  	int (*soc_revision)(u32 *socrev, u64 *socuid);  };
> > >
> > > +struct imx8m_soc_priv {
> > > +	struct soc_device *soc_dev;
> > > +	struct platform_device *cpufreq_dev; };
> > > +
> > >  #ifdef CONFIG_HAVE_ARM_SMCCC
> > >  static u32 imx8mq_soc_revision_from_atf(void)
> > >  {
> > > @@ -198,7 +203,7 @@ static int imx8m_soc_probe(struct
> > platform_device *pdev)
> > >  	const struct imx8_soc_data *data;
> > >  	struct device *dev = &pdev->dev;
> > >  	const struct of_device_id *id;
> > > -	struct soc_device *soc_dev;
> > > +	struct imx8m_soc_priv *priv;
> > >  	u32 soc_rev = 0;
> > >  	u64 soc_uid = 0;
> > >  	int ret;
> > > @@ -207,6 +212,10 @@ static int imx8m_soc_probe(struct
> > platform_device *pdev)
> > >  	if (!soc_dev_attr)
> > >  		return -ENOMEM;
> > >
> > > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > > +	if (!priv)
> > > +		return -ENOMEM;
> > > +
> > >  	soc_dev_attr->family = "Freescale i.MX";
> > >
> > >  	ret = of_property_read_string(of_root, "model",
> > > &soc_dev_attr->machine); @@ -235,21 +244,34 @@ static int
> > imx8m_soc_probe(struct platform_device *pdev)
> > >  	if (!soc_dev_attr->serial_number)
> > >  		return -ENOMEM;
> > >
> > > -	soc_dev = soc_device_register(soc_dev_attr);
> > > -	if (IS_ERR(soc_dev))
> > > -		return PTR_ERR(soc_dev);
> > > +	priv->soc_dev = soc_device_register(soc_dev_attr);
> > > +	if (IS_ERR(priv->soc_dev))
> > > +		return PTR_ERR(priv->soc_dev);
> > >
> > >  	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
> > >  		soc_dev_attr->revision);
> > >
> > >  	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> > > -		platform_device_register_simple("imx-cpufreq-dt", -1,
> > NULL, 0);
> > > +		priv->cpufreq_dev =
> > > +platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> > 
> > If CONFIG_ARM_IMX_CPUFREQ_DT is enabled, I asusme that
> > platform_device_register_simple() shouldn't fail else it will be an error,
> > right? Therefore I would like to add the 'if(!IS_ERR())' check here
> > instead of the remove function.
> 
> You mean below?
> dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> if (!IS_ERR(dev))
>    plat->cpufreq_dev = dev;
> else
>   pr_err("Failed to register imx-cpufreq-dt: %d\n", ERR_PTR(dev))?

Hmm, I'm not sure why we do not have error check on
platform_device_register_simple().  Shouldn't we do the following?

	priv->cpufreq_dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
	if (IS_ERR(priv->cpufreq_dev))
		return PTR_ERR(priv->cpufreq_dev);

Then I'm with Marco that we only need to check 'if (priv->cpufreq_dev)' in
remove function.

Shawn

RE: [PATCH] soc: imx8m: Add remove function

[Peng Fan]

Hi Shawn,

> Subject: Re: [PATCH] soc: imx8m: Add remove function
> 
> On Mon, Dec 09, 2024 at 08:26:48AM +0000, Peng Fan wrote:
> > > Subject: Re: [PATCH] soc: imx8m: Add remove function
> > >
> > > On 24-12-06, Peng Fan (OSS) wrote:
> > > > From: Peng Fan <peng.fan@nxp.com>
> > > >
> > > > Unregister the cpufreq device and soc device in remove path,
> > > otherwise
> > > > there will be warning when do removing test:
> > > > sysfs: cannot create duplicate filename '/devices/platform/imx-
> > > cpufreq-dt'
> > > > CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted
> > > > 6.13.0-rc1-next-20241204 Hardware name: NXP i.MX8MPlus EVK
> > > board (DT)
> > > >
> > > > Fixes: 9cc832d37799 ("soc: imx8m: Probe the SoC driver as
> platform
> > > > driver")
> > > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > > ---
> > > >  drivers/soc/imx/soc-imx8m.c | 32
> +++++++++++++++++++++++++++----
> > > -
> > > >  1 file changed, 27 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-
> > > imx8m.c
> > > > index 8ac7658e3d52..8c368947d1e5 100644
> > > > --- a/drivers/soc/imx/soc-imx8m.c
> > > > +++ b/drivers/soc/imx/soc-imx8m.c
> > > > @@ -33,6 +33,11 @@ struct imx8_soc_data {
> > > >  	int (*soc_revision)(u32 *socrev, u64 *socuid);  };
> > > >
> > > > +struct imx8m_soc_priv {
> > > > +	struct soc_device *soc_dev;
> > > > +	struct platform_device *cpufreq_dev; };
> > > > +
> > > >  #ifdef CONFIG_HAVE_ARM_SMCCC
> > > >  static u32 imx8mq_soc_revision_from_atf(void)
> > > >  {
> > > > @@ -198,7 +203,7 @@ static int imx8m_soc_probe(struct
> > > platform_device *pdev)
> > > >  	const struct imx8_soc_data *data;
> > > >  	struct device *dev = &pdev->dev;
> > > >  	const struct of_device_id *id;
> > > > -	struct soc_device *soc_dev;
> > > > +	struct imx8m_soc_priv *priv;
> > > >  	u32 soc_rev = 0;
> > > >  	u64 soc_uid = 0;
> > > >  	int ret;
> > > > @@ -207,6 +212,10 @@ static int imx8m_soc_probe(struct
> > > platform_device *pdev)
> > > >  	if (!soc_dev_attr)
> > > >  		return -ENOMEM;
> > > >
> > > > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > > > +	if (!priv)
> > > > +		return -ENOMEM;
> > > > +
> > > >  	soc_dev_attr->family = "Freescale i.MX";
> > > >
> > > >  	ret = of_property_read_string(of_root, "model",
> > > > &soc_dev_attr->machine); @@ -235,21 +244,34 @@ static int
> > > imx8m_soc_probe(struct platform_device *pdev)
> > > >  	if (!soc_dev_attr->serial_number)
> > > >  		return -ENOMEM;
> > > >
> > > > -	soc_dev = soc_device_register(soc_dev_attr);
> > > > -	if (IS_ERR(soc_dev))
> > > > -		return PTR_ERR(soc_dev);
> > > > +	priv->soc_dev = soc_device_register(soc_dev_attr);
> > > > +	if (IS_ERR(priv->soc_dev))
> > > > +		return PTR_ERR(priv->soc_dev);
> > > >
> > > >  	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
> > > >  		soc_dev_attr->revision);
> > > >
> > > >  	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> > > > -		platform_device_register_simple("imx-cpufreq-dt", -1,
> > > NULL, 0);
> > > > +		priv->cpufreq_dev =
> > > > +platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> > >
> > > If CONFIG_ARM_IMX_CPUFREQ_DT is enabled, I asusme that
> > > platform_device_register_simple() shouldn't fail else it will be an
> > > error, right? Therefore I would like to add the 'if(!IS_ERR())'
> > > check here instead of the remove function.
> >
> > You mean below?
> > dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> > if (!IS_ERR(dev))
> >    plat->cpufreq_dev = dev;
> > else
> >   pr_err("Failed to register imx-cpufreq-dt: %d\n", ERR_PTR(dev))?
> 
> Hmm, I'm not sure why we do not have error check on
> platform_device_register_simple().  Shouldn't we do the following?
> 
> 	priv->cpufreq_dev = platform_device_register_simple("imx-
> cpufreq-dt", -1, NULL, 0);
> 	if (IS_ERR(priv->cpufreq_dev))
> 		return PTR_ERR(priv->cpufreq_dev);
> 
> Then I'm with Marco that we only need to check 'if (priv-
> >cpufreq_dev)' in remove function.

Please give a look on v3:
https://lore.kernel.org/all/20241219145029.1776006-1-peng.fan@oss.nxp.com/

Thanks,
Peng.

> 
> Shawn