[PATCH 0/2 v2] mtd: onenand: samsung: Simplify code and fix leaks in error handling paths

[PATCH 0/2 v2] mtd: onenand: samsung: Simplify code and fix leaks in error handling paths

[Christophe JAILLET]

The first patch converts 's3c_onenand_probe()' to devm_ functions.
This fixes a leak in one path (line 872).
This also free_irq which was not handled at all. (I hope I'm correct :) )

The 2nd patch is about an un-handled error code which looks spurious.
Not sure if I'm right.


While compile-testing it, I had to tweak the code because I don't have any
cross-compiler.
I commented the line "#include <asm/mach/flash.h>" and the compilation
succeeded. So maybe, this include is also useless.
I've left it as-is, though.


Theses patches have been compile-tested-only.


Christophe JAILLET (2):
  mtd: onenand: samsung: use devm_ function to simplify code and fix
    some leaks
  mtd: onenand: samsung: return an error if
    'mtd_device_parse_register()' fails

 drivers/mtd/onenand/samsung.c | 169 +++++++++---------------------------------
 1 file changed, 34 insertions(+), 135 deletions(-)

-- 
2.14.1

[PATCH 1/2 v2] mtd: onenand: samsung: use devm_ function to simplify code and fix some leaks

[Christophe JAILLET]

Convert all error handling code in 's3c_onenand_probe()' to
resource-managed alternatives in order to simplify code.

This fixes a resource leak if 'platform_get_resource()' fails at line 872.

The 'request_irq()' at line 971 was also un-balanced. It is now
resource-managed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested-only

v2: use devm_ioremap_resource()
---
 drivers/mtd/onenand/samsung.c | 164 ++++++++----------------------------------
 1 file changed, 29 insertions(+), 135 deletions(-)

diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
index af0ac1a7bf8f..2e562c224060 100644
--- a/drivers/mtd/onenand/samsung.c
+++ b/drivers/mtd/onenand/samsung.c
@@ -129,16 +129,13 @@ struct s3c_onenand {
 	struct platform_device	*pdev;
 	enum soc_type	type;
 	void __iomem	*base;
-	struct resource *base_res;
 	void __iomem	*ahb_addr;
-	struct resource *ahb_res;
 	int		bootram_command;
 	void __iomem	*page_buf;
 	void __iomem	*oob_buf;
 	unsigned int	(*mem_addr)(int fba, int fpa, int fsa);
 	unsigned int	(*cmd_map)(unsigned int type, unsigned int val);
 	void __iomem	*dma_addr;
-	struct resource *dma_res;
 	unsigned long	phys_base;
 	struct completion	complete;
 };
@@ -851,15 +848,13 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	/* No need to check pdata. the platform data is optional */
 
 	size = sizeof(struct mtd_info) + sizeof(struct onenand_chip);
-	mtd = kzalloc(size, GFP_KERNEL);
+	mtd = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
 	if (!mtd)
 		return -ENOMEM;
 
-	onenand = kzalloc(sizeof(struct s3c_onenand), GFP_KERNEL);
-	if (!onenand) {
-		err = -ENOMEM;
-		goto onenand_fail;
-	}
+	onenand = devm_kzalloc(&pdev->dev, sizeof(struct s3c_onenand), GFP_KERNEL);
+	if (!onenand)
+		return -ENOMEM;
 
 	this = (struct onenand_chip *) &mtd[1];
 	mtd->priv = this;
@@ -870,26 +865,10 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	s3c_onenand_setup(mtd);
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!r) {
-		dev_err(&pdev->dev, "no memory resource defined\n");
-		return -ENOENT;
-		goto ahb_resource_failed;
-	}
+	onenand->base = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(onenand->base))
+		return PTR_ERR(onenand->base);
 
-	onenand->base_res = request_mem_region(r->start, resource_size(r),
-					       pdev->name);
-	if (!onenand->base_res) {
-		dev_err(&pdev->dev, "failed to request memory resource\n");
-		err = -EBUSY;
-		goto resource_failed;
-	}
-
-	onenand->base = ioremap(r->start, resource_size(r));
-	if (!onenand->base) {
-		dev_err(&pdev->dev, "failed to map memory resource\n");
-		err = -EFAULT;
-		goto ioremap_failed;
-	}
 	/* Set onenand_chip also */
 	this->base = onenand->base;
 
@@ -898,40 +877,20 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 
 	if (onenand->type != TYPE_S5PC110) {
 		r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-		if (!r) {
-			dev_err(&pdev->dev, "no buffer memory resource defined\n");
-			err = -ENOENT;
-			goto ahb_resource_failed;
-		}
-
-		onenand->ahb_res = request_mem_region(r->start, resource_size(r),
-						      pdev->name);
-		if (!onenand->ahb_res) {
-			dev_err(&pdev->dev, "failed to request buffer memory resource\n");
-			err = -EBUSY;
-			goto ahb_resource_failed;
-		}
-
-		onenand->ahb_addr = ioremap(r->start, resource_size(r));
-		if (!onenand->ahb_addr) {
-			dev_err(&pdev->dev, "failed to map buffer memory resource\n");
-			err = -EINVAL;
-			goto ahb_ioremap_failed;
-		}
+		onenand->ahb_addr = devm_ioremap_resource(&pdev->dev, r);
+		if (IS_ERR(onenand->ahb_addr))
+			return PTR_ERR(onenand->ahb_addr);
 
 		/* Allocate 4KiB BufferRAM */
-		onenand->page_buf = kzalloc(SZ_4K, GFP_KERNEL);
-		if (!onenand->page_buf) {
-			err = -ENOMEM;
-			goto page_buf_fail;
-		}
+		onenand->page_buf = devm_kzalloc(&pdev->dev, SZ_4K,
+						 GFP_KERNEL);
+		if (!onenand->page_buf)
+			return -ENOMEM;
 
 		/* Allocate 128 SpareRAM */
-		onenand->oob_buf = kzalloc(128, GFP_KERNEL);
-		if (!onenand->oob_buf) {
-			err = -ENOMEM;
-			goto oob_buf_fail;
-		}
+		onenand->oob_buf = devm_kzalloc(&pdev->dev, 128, GFP_KERNEL);
+		if (!onenand->oob_buf)
+			return -ENOMEM;
 
 		/* S3C doesn't handle subpage write */
 		mtd->subpage_sft = 0;
@@ -939,28 +898,11 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 
 	} else { /* S5PC110 */
 		r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-		if (!r) {
-			dev_err(&pdev->dev, "no dma memory resource defined\n");
-			err = -ENOENT;
-			goto dma_resource_failed;
-		}
-
-		onenand->dma_res = request_mem_region(r->start, resource_size(r),
-						      pdev->name);
-		if (!onenand->dma_res) {
-			dev_err(&pdev->dev, "failed to request dma memory resource\n");
-			err = -EBUSY;
-			goto dma_resource_failed;
-		}
+		onenand->dma_addr = devm_ioremap_resource(&pdev->dev, r);
+		if (IS_ERR(onenand->dma_addr))
+			return PTR_ERR(onenand->dma_addr);
 
-		onenand->dma_addr = ioremap(r->start, resource_size(r));
-		if (!onenand->dma_addr) {
-			dev_err(&pdev->dev, "failed to map dma memory resource\n");
-			err = -EINVAL;
-			goto dma_ioremap_failed;
-		}
-
-		onenand->phys_base = onenand->base_res->start;
+		onenand->phys_base = r->start;
 
 		s5pc110_dma_ops = s5pc110_dma_poll;
 		/* Interrupt support */
@@ -968,19 +910,19 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 		if (r) {
 			init_completion(&onenand->complete);
 			s5pc110_dma_ops = s5pc110_dma_irq;
-			err = request_irq(r->start, s5pc110_onenand_irq,
-					IRQF_SHARED, "onenand", &onenand);
+			err = devm_request_irq(&pdev->dev, r->start,
+					       s5pc110_onenand_irq,
+					       IRQF_SHARED, "onenand",
+					       &onenand);
 			if (err) {
 				dev_err(&pdev->dev, "failed to get irq\n");
-				goto scan_failed;
+				return err;
 			}
 		}
 	}
 
-	if (onenand_scan(mtd, 1)) {
-		err = -EFAULT;
-		goto scan_failed;
-	}
+	if (onenand_scan(mtd, 1))
+		return -EFAULT;
 
 	if (onenand->type != TYPE_S5PC110) {
 		/* S3C doesn't handle subpage write */
@@ -998,36 +940,6 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, mtd);
 
 	return 0;
-
-scan_failed:
-	if (onenand->dma_addr)
-		iounmap(onenand->dma_addr);
-dma_ioremap_failed:
-	if (onenand->dma_res)
-		release_mem_region(onenand->dma_res->start,
-				   resource_size(onenand->dma_res));
-	kfree(onenand->oob_buf);
-oob_buf_fail:
-	kfree(onenand->page_buf);
-page_buf_fail:
-	if (onenand->ahb_addr)
-		iounmap(onenand->ahb_addr);
-ahb_ioremap_failed:
-	if (onenand->ahb_res)
-		release_mem_region(onenand->ahb_res->start,
-				   resource_size(onenand->ahb_res));
-dma_resource_failed:
-ahb_resource_failed:
-	iounmap(onenand->base);
-ioremap_failed:
-	if (onenand->base_res)
-		release_mem_region(onenand->base_res->start,
-				   resource_size(onenand->base_res));
-resource_failed:
-	kfree(onenand);
-onenand_fail:
-	kfree(mtd);
-	return err;
 }
 
 static int s3c_onenand_remove(struct platform_device *pdev)
@@ -1035,25 +947,7 @@ static int s3c_onenand_remove(struct platform_device *pdev)
 	struct mtd_info *mtd = platform_get_drvdata(pdev);
 
 	onenand_release(mtd);
-	if (onenand->ahb_addr)
-		iounmap(onenand->ahb_addr);
-	if (onenand->ahb_res)
-		release_mem_region(onenand->ahb_res->start,
-				   resource_size(onenand->ahb_res));
-	if (onenand->dma_addr)
-		iounmap(onenand->dma_addr);
-	if (onenand->dma_res)
-		release_mem_region(onenand->dma_res->start,
-				   resource_size(onenand->dma_res));
-
-	iounmap(onenand->base);
-	release_mem_region(onenand->base_res->start,
-			   resource_size(onenand->base_res));
-
-	kfree(onenand->oob_buf);
-	kfree(onenand->page_buf);
-	kfree(onenand);
-	kfree(mtd);
+
 	return 0;
 }
 
-- 
2.14.1

[PATCH 2/2 v2] mtd: onenand: samsung: return an error if 'mtd_device_parse_register()' fails

[Christophe JAILLET]

If 'mtd_device_parse_register()' fails, we still return 0 which mean
success.
Return the error code instead, as done in all the other error handling
paths.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested-only

v2: call 'onenand_release()' to undo 'onenand_scan()'
---
 drivers/mtd/onenand/samsung.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
index 2e562c224060..4031f750f334 100644
--- a/drivers/mtd/onenand/samsung.c
+++ b/drivers/mtd/onenand/samsung.c
@@ -936,6 +936,11 @@ static int s3c_onenand_probe(struct platform_device *pdev)
 	err = mtd_device_parse_register(mtd, NULL, NULL,
 					pdata ? pdata->parts : NULL,
 					pdata ? pdata->nr_parts : 0);
+	if (err) {
+		dev_err(&pdev->dev, "failed to parse partitions and register the MTD device\n");
+		onenand_release(mtd);
+		return err;
+	}
 
 	platform_set_drvdata(pdev, mtd);
 
-- 
2.14.1

Re: [PATCH 0/2 v2] mtd: onenand: samsung: Simplify code and fix leaks in error handling paths

[Boris Brezillon]

On Sat,  9 Dec 2017 08:24:03 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> The first patch converts 's3c_onenand_probe()' to devm_ functions.
> This fixes a leak in one path (line 872).
> This also free_irq which was not handled at all. (I hope I'm correct :) )
> 
> The 2nd patch is about an un-handled error code which looks spurious.
> Not sure if I'm right.
> 
> 
> While compile-testing it, I had to tweak the code because I don't have any
> cross-compiler.

Oh come on! It's really not that complicated to install an arm toolchain
and cross compile the kernel.

> I commented the line "#include <asm/mach/flash.h>" and the compilation
> succeeded. So maybe, this include is also useless.

Yep, it's not surprising, the driver is really in a poor state. I also
noticed that buffers allocated with kmalloc are flagged as __iomem
regions, which is obviously wrong. And I fear we'll find plenty of other
issues if we dig a bit more.

> I've left it as-is, though.

Can be fixed in another patch.

> 
> 
> Theses patches have been compile-tested-only.
> 
> 
> Christophe JAILLET (2):
>   mtd: onenand: samsung: use devm_ function to simplify code and fix
>     some leaks
>   mtd: onenand: samsung: return an error if
>     'mtd_device_parse_register()' fails
> 
>  drivers/mtd/onenand/samsung.c | 169 +++++++++---------------------------------
>  1 file changed, 34 insertions(+), 135 deletions(-)
> 

Re: [PATCH 1/2 v2] mtd: onenand: samsung: use devm_ function to simplify code and fix some leaks

[Boris Brezillon]

On Sat,  9 Dec 2017 08:24:04 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> Convert all error handling code in 's3c_onenand_probe()' to
> resource-managed alternatives in order to simplify code.
> 
> This fixes a resource leak if 'platform_get_resource()' fails at line 872.
> 
> The 'request_irq()' at line 971 was also un-balanced. It is now
> resource-managed.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Compile tested-only
> 
> v2: use devm_ioremap_resource()
> ---
>  drivers/mtd/onenand/samsung.c | 164 ++++++++----------------------------------
>  1 file changed, 29 insertions(+), 135 deletions(-)
> 
> diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
> index af0ac1a7bf8f..2e562c224060 100644
> --- a/drivers/mtd/onenand/samsung.c
> +++ b/drivers/mtd/onenand/samsung.c
> @@ -129,16 +129,13 @@ struct s3c_onenand {
>  	struct platform_device	*pdev;
>  	enum soc_type	type;
>  	void __iomem	*base;
> -	struct resource *base_res;
>  	void __iomem	*ahb_addr;
> -	struct resource *ahb_res;
>  	int		bootram_command;
>  	void __iomem	*page_buf;
>  	void __iomem	*oob_buf;
>  	unsigned int	(*mem_addr)(int fba, int fpa, int fsa);
>  	unsigned int	(*cmd_map)(unsigned int type, unsigned int val);
>  	void __iomem	*dma_addr;
> -	struct resource *dma_res;
>  	unsigned long	phys_base;
>  	struct completion	complete;
>  };
> @@ -851,15 +848,13 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	/* No need to check pdata. the platform data is optional */
>  
>  	size = sizeof(struct mtd_info) + sizeof(struct onenand_chip);
> -	mtd = kzalloc(size, GFP_KERNEL);
> +	mtd = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
>  	if (!mtd)
>  		return -ENOMEM;
>  
> -	onenand = kzalloc(sizeof(struct s3c_onenand), GFP_KERNEL);
> -	if (!onenand) {
> -		err = -ENOMEM;
> -		goto onenand_fail;
> -	}
> +	onenand = devm_kzalloc(&pdev->dev, sizeof(struct s3c_onenand), GFP_KERNEL);
> +	if (!onenand)
> +		return -ENOMEM;
>  
>  	this = (struct onenand_chip *) &mtd[1];
>  	mtd->priv = this;
> @@ -870,26 +865,10 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	s3c_onenand_setup(mtd);
>  
>  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	if (!r) {
> -		dev_err(&pdev->dev, "no memory resource defined\n");
> -		return -ENOENT;
> -		goto ahb_resource_failed;
> -	}
> +	onenand->base = devm_ioremap_resource(&pdev->dev, r);
> +	if (IS_ERR(onenand->base))
> +		return PTR_ERR(onenand->base);
>  
> -	onenand->base_res = request_mem_region(r->start, resource_size(r),
> -					       pdev->name);
> -	if (!onenand->base_res) {
> -		dev_err(&pdev->dev, "failed to request memory resource\n");
> -		err = -EBUSY;
> -		goto resource_failed;
> -	}
> -
> -	onenand->base = ioremap(r->start, resource_size(r));
> -	if (!onenand->base) {
> -		dev_err(&pdev->dev, "failed to map memory resource\n");
> -		err = -EFAULT;
> -		goto ioremap_failed;
> -	}
>  	/* Set onenand_chip also */
>  	this->base = onenand->base;
>  
> @@ -898,40 +877,20 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  
>  	if (onenand->type != TYPE_S5PC110) {
>  		r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -		if (!r) {
> -			dev_err(&pdev->dev, "no buffer memory resource defined\n");
> -			err = -ENOENT;
> -			goto ahb_resource_failed;
> -		}
> -
> -		onenand->ahb_res = request_mem_region(r->start, resource_size(r),
> -						      pdev->name);
> -		if (!onenand->ahb_res) {
> -			dev_err(&pdev->dev, "failed to request buffer memory resource\n");
> -			err = -EBUSY;
> -			goto ahb_resource_failed;
> -		}
> -
> -		onenand->ahb_addr = ioremap(r->start, resource_size(r));
> -		if (!onenand->ahb_addr) {
> -			dev_err(&pdev->dev, "failed to map buffer memory resource\n");
> -			err = -EINVAL;
> -			goto ahb_ioremap_failed;
> -		}
> +		onenand->ahb_addr = devm_ioremap_resource(&pdev->dev, r);
> +		if (IS_ERR(onenand->ahb_addr))
> +			return PTR_ERR(onenand->ahb_addr);
>  
>  		/* Allocate 4KiB BufferRAM */
> -		onenand->page_buf = kzalloc(SZ_4K, GFP_KERNEL);
> -		if (!onenand->page_buf) {
> -			err = -ENOMEM;
> -			goto page_buf_fail;
> -		}
> +		onenand->page_buf = devm_kzalloc(&pdev->dev, SZ_4K,
> +						 GFP_KERNEL);
> +		if (!onenand->page_buf)
> +			return -ENOMEM;
>  
>  		/* Allocate 128 SpareRAM */
> -		onenand->oob_buf = kzalloc(128, GFP_KERNEL);
> -		if (!onenand->oob_buf) {
> -			err = -ENOMEM;
> -			goto oob_buf_fail;
> -		}
> +		onenand->oob_buf = devm_kzalloc(&pdev->dev, 128, GFP_KERNEL);
> +		if (!onenand->oob_buf)
> +			return -ENOMEM;
>  
>  		/* S3C doesn't handle subpage write */
>  		mtd->subpage_sft = 0;
> @@ -939,28 +898,11 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  
>  	} else { /* S5PC110 */
>  		r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -		if (!r) {
> -			dev_err(&pdev->dev, "no dma memory resource defined\n");
> -			err = -ENOENT;
> -			goto dma_resource_failed;
> -		}
> -
> -		onenand->dma_res = request_mem_region(r->start, resource_size(r),
> -						      pdev->name);
> -		if (!onenand->dma_res) {
> -			dev_err(&pdev->dev, "failed to request dma memory resource\n");
> -			err = -EBUSY;
> -			goto dma_resource_failed;
> -		}
> +		onenand->dma_addr = devm_ioremap_resource(&pdev->dev, r);
> +		if (IS_ERR(onenand->dma_addr))
> +			return PTR_ERR(onenand->dma_addr);
>  
> -		onenand->dma_addr = ioremap(r->start, resource_size(r));
> -		if (!onenand->dma_addr) {
> -			dev_err(&pdev->dev, "failed to map dma memory resource\n");
> -			err = -EINVAL;
> -			goto dma_ioremap_failed;
> -		}
> -
> -		onenand->phys_base = onenand->base_res->start;
> +		onenand->phys_base = r->start;

This is wrong, ->phys_base should be assigned to base_res->start not
dma_res->start (I pointed it in my previous review).

>  
>  		s5pc110_dma_ops = s5pc110_dma_poll;
>  		/* Interrupt support */
> @@ -968,19 +910,19 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  		if (r) {
>  			init_completion(&onenand->complete);
>  			s5pc110_dma_ops = s5pc110_dma_irq;
> -			err = request_irq(r->start, s5pc110_onenand_irq,
> -					IRQF_SHARED, "onenand", &onenand);
> +			err = devm_request_irq(&pdev->dev, r->start,
> +					       s5pc110_onenand_irq,
> +					       IRQF_SHARED, "onenand",
> +					       &onenand);
>  			if (err) {
>  				dev_err(&pdev->dev, "failed to get irq\n");
> -				goto scan_failed;
> +				return err;
>  			}
>  		}
>  	}
>  
> -	if (onenand_scan(mtd, 1)) {
> -		err = -EFAULT;
> -		goto scan_failed;
> -	}
> +	if (onenand_scan(mtd, 1))
> +		return -EFAULT;

Not related to this patch, but we should return the error code returned
by onenand_scan() here instead of always returning -EFAULT.

>  
>  	if (onenand->type != TYPE_S5PC110) {
>  		/* S3C doesn't handle subpage write */
> @@ -998,36 +940,6 @@ static int s3c_onenand_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, mtd);
>  
>  	return 0;
> -
> -scan_failed:
> -	if (onenand->dma_addr)
> -		iounmap(onenand->dma_addr);
> -dma_ioremap_failed:
> -	if (onenand->dma_res)
> -		release_mem_region(onenand->dma_res->start,
> -				   resource_size(onenand->dma_res));
> -	kfree(onenand->oob_buf);
> -oob_buf_fail:
> -	kfree(onenand->page_buf);
> -page_buf_fail:
> -	if (onenand->ahb_addr)
> -		iounmap(onenand->ahb_addr);
> -ahb_ioremap_failed:
> -	if (onenand->ahb_res)
> -		release_mem_region(onenand->ahb_res->start,
> -				   resource_size(onenand->ahb_res));
> -dma_resource_failed:
> -ahb_resource_failed:
> -	iounmap(onenand->base);
> -ioremap_failed:
> -	if (onenand->base_res)
> -		release_mem_region(onenand->base_res->start,
> -				   resource_size(onenand->base_res));
> -resource_failed:
> -	kfree(onenand);
> -onenand_fail:
> -	kfree(mtd);
> -	return err;
>  }
>  
>  static int s3c_onenand_remove(struct platform_device *pdev)
> @@ -1035,25 +947,7 @@ static int s3c_onenand_remove(struct platform_device *pdev)
>  	struct mtd_info *mtd = platform_get_drvdata(pdev);
>  
>  	onenand_release(mtd);
> -	if (onenand->ahb_addr)
> -		iounmap(onenand->ahb_addr);
> -	if (onenand->ahb_res)
> -		release_mem_region(onenand->ahb_res->start,
> -				   resource_size(onenand->ahb_res));
> -	if (onenand->dma_addr)
> -		iounmap(onenand->dma_addr);
> -	if (onenand->dma_res)
> -		release_mem_region(onenand->dma_res->start,
> -				   resource_size(onenand->dma_res));
> -
> -	iounmap(onenand->base);
> -	release_mem_region(onenand->base_res->start,
> -			   resource_size(onenand->base_res));
> -
> -	kfree(onenand->oob_buf);
> -	kfree(onenand->page_buf);
> -	kfree(onenand);
> -	kfree(mtd);
> +
>  	return 0;
>  }
>