[PATCH] power: reset: at91-reset: free resources on exit path

[PATCH] power: reset: at91-reset: free resources on exit path

[Claudiu Beznea]

Free resources on exit path (failure path of probe and remove).

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 3ff9d93a5226..2ff7833153b6 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 			if (!reset->ramc_base[idx]) {
 				dev_err(&pdev->dev, "Could not map ram controller address\n");
 				of_node_put(np);
-				return -ENODEV;
+				ret = -ENODEV;
+				goto unmap;
 			}
 			idx++;
 		}
@@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 	reset->args = (u32)match->data;
 
 	reset->sclk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(reset->sclk))
-		return PTR_ERR(reset->sclk);
+	if (IS_ERR(reset->sclk)) {
+		ret = PTR_ERR(reset->sclk);
+		goto unmap;
+	}
 
 	ret = clk_prepare_enable(reset->sclk);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not enable slow clock\n");
-		return ret;
+		goto unmap;
 	}
 
 	platform_set_drvdata(pdev, reset);
@@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 	ret = register_restart_handler(&reset->nb);
 	if (ret) {
 		clk_disable_unprepare(reset->sclk);
-		return ret;
+		goto unmap;
 	}
 
 	at91_reset_status(pdev, reset->rstc_base);
 
 	return 0;
+
+unmap:
+	iounmap(reset->rstc_base);
+	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
+		iounmap(reset->ramc_base[idx]);
+
+	return ret;
 }
 
 static int __exit at91_reset_remove(struct platform_device *pdev)
 {
 	struct at91_reset *reset = platform_get_drvdata(pdev);
+	int idx;
 
 	unregister_restart_handler(&reset->nb);
 	clk_disable_unprepare(reset->sclk);
 
+	iounmap(reset->rstc_base);
+	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
+		iounmap(reset->ramc_base[idx]);
+
 	return 0;
 }
 
-- 
2.25.1

[PATCH] power: reset: at91-reset: free resources on exit path

[Claudiu Beznea]

Free resources on exit path (failure path of probe and remove).

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 3ff9d93a5226..2ff7833153b6 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 			if (!reset->ramc_base[idx]) {
 				dev_err(&pdev->dev, "Could not map ram controller address\n");
 				of_node_put(np);
-				return -ENODEV;
+				ret = -ENODEV;
+				goto unmap;
 			}
 			idx++;
 		}
@@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 	reset->args = (u32)match->data;
 
 	reset->sclk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(reset->sclk))
-		return PTR_ERR(reset->sclk);
+	if (IS_ERR(reset->sclk)) {
+		ret = PTR_ERR(reset->sclk);
+		goto unmap;
+	}
 
 	ret = clk_prepare_enable(reset->sclk);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not enable slow clock\n");
-		return ret;
+		goto unmap;
 	}
 
 	platform_set_drvdata(pdev, reset);
@@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 	ret = register_restart_handler(&reset->nb);
 	if (ret) {
 		clk_disable_unprepare(reset->sclk);
-		return ret;
+		goto unmap;
 	}
 
 	at91_reset_status(pdev, reset->rstc_base);
 
 	return 0;
+
+unmap:
+	iounmap(reset->rstc_base);
+	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
+		iounmap(reset->ramc_base[idx]);
+
+	return ret;
 }
 
 static int __exit at91_reset_remove(struct platform_device *pdev)
 {
 	struct at91_reset *reset = platform_get_drvdata(pdev);
+	int idx;
 
 	unregister_restart_handler(&reset->nb);
 	clk_disable_unprepare(reset->sclk);
 
+	iounmap(reset->rstc_base);
+	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
+		iounmap(reset->ramc_base[idx]);
+
 	return 0;
 }
 
-- 
2.25.1


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Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Nicolas Ferre]

On 09/02/2021 at 12:01, Claudiu Beznea wrote:
> Free resources on exit path (failure path of probe and remove).

I'm not sure we can use this driver as a module anyway.

Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(), 
even in loop, and avoid having to deal with exit path?

> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>   1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
> index 3ff9d93a5226..2ff7833153b6 100644
> --- a/drivers/power/reset/at91-reset.c
> +++ b/drivers/power/reset/at91-reset.c
> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   			if (!reset->ramc_base[idx]) {
>   				dev_err(&pdev->dev, "Could not map ram controller address\n");
>   				of_node_put(np);
> -				return -ENODEV;
> +				ret = -ENODEV;
> +				goto unmap;
>   			}
>   			idx++;
>   		}
> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   	reset->args = (u32)match->data;
>   
>   	reset->sclk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(reset->sclk))
> -		return PTR_ERR(reset->sclk);
> +	if (IS_ERR(reset->sclk)) {
> +		ret = PTR_ERR(reset->sclk);
> +		goto unmap;
> +	}
>   
>   	ret = clk_prepare_enable(reset->sclk);
>   	if (ret) {
>   		dev_err(&pdev->dev, "Could not enable slow clock\n");
> -		return ret;
> +		goto unmap;
>   	}
>   
>   	platform_set_drvdata(pdev, reset);
> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   	ret = register_restart_handler(&reset->nb);
>   	if (ret) {
>   		clk_disable_unprepare(reset->sclk);
> -		return ret;
> +		goto unmap;
>   	}
>   
>   	at91_reset_status(pdev, reset->rstc_base);
>   
>   	return 0;
> +
> +unmap:
> +	iounmap(reset->rstc_base);
> +	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
> +		iounmap(reset->ramc_base[idx]);

But if we keep this loop, I have the feeling that some kind of 
"of_node_put()" is needed as well.

> +
> +	return ret;
>   }
>   
>   static int __exit at91_reset_remove(struct platform_device *pdev)
>   {
>   	struct at91_reset *reset = platform_get_drvdata(pdev);
> +	int idx;
>   
>   	unregister_restart_handler(&reset->nb);
>   	clk_disable_unprepare(reset->sclk);
>   
> +	iounmap(reset->rstc_base);
> +	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
> +		iounmap(reset->ramc_base[idx]);

Ditto

> +
>   	return 0;
>   }
>   
> 


-- 
Nicolas Ferre

Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Nicolas Ferre]

On 09/02/2021 at 12:01, Claudiu Beznea wrote:
> Free resources on exit path (failure path of probe and remove).

I'm not sure we can use this driver as a module anyway.

Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(), 
even in loop, and avoid having to deal with exit path?

> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>   1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
> index 3ff9d93a5226..2ff7833153b6 100644
> --- a/drivers/power/reset/at91-reset.c
> +++ b/drivers/power/reset/at91-reset.c
> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   			if (!reset->ramc_base[idx]) {
>   				dev_err(&pdev->dev, "Could not map ram controller address\n");
>   				of_node_put(np);
> -				return -ENODEV;
> +				ret = -ENODEV;
> +				goto unmap;
>   			}
>   			idx++;
>   		}
> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   	reset->args = (u32)match->data;
>   
>   	reset->sclk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(reset->sclk))
> -		return PTR_ERR(reset->sclk);
> +	if (IS_ERR(reset->sclk)) {
> +		ret = PTR_ERR(reset->sclk);
> +		goto unmap;
> +	}
>   
>   	ret = clk_prepare_enable(reset->sclk);
>   	if (ret) {
>   		dev_err(&pdev->dev, "Could not enable slow clock\n");
> -		return ret;
> +		goto unmap;
>   	}
>   
>   	platform_set_drvdata(pdev, reset);
> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   	ret = register_restart_handler(&reset->nb);
>   	if (ret) {
>   		clk_disable_unprepare(reset->sclk);
> -		return ret;
> +		goto unmap;
>   	}
>   
>   	at91_reset_status(pdev, reset->rstc_base);
>   
>   	return 0;
> +
> +unmap:
> +	iounmap(reset->rstc_base);
> +	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
> +		iounmap(reset->ramc_base[idx]);

But if we keep this loop, I have the feeling that some kind of 
"of_node_put()" is needed as well.

> +
> +	return ret;
>   }
>   
>   static int __exit at91_reset_remove(struct platform_device *pdev)
>   {
>   	struct at91_reset *reset = platform_get_drvdata(pdev);
> +	int idx;
>   
>   	unregister_restart_handler(&reset->nb);
>   	clk_disable_unprepare(reset->sclk);
>   
> +	iounmap(reset->rstc_base);
> +	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
> +		iounmap(reset->ramc_base[idx]);

Ditto

> +
>   	return 0;
>   }
>   
> 


-- 
Nicolas Ferre

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Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Claudiu.Beznea]

On 31.03.2021 11:18, Nicolas Ferre wrote:
> On 09/02/2021 at 12:01, Claudiu Beznea wrote:
>> Free resources on exit path (failure path of probe and remove).
> 
> I'm not sure we can use this driver as a module anyway.
> 
> Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(),
> even in loop, and avoid having to deal with exit path?

For:
reset->rstc_base = of_iomap(pdev->dev.of_node, 0);

it should work.

For the maps in the loop I have to double check. Basically, the struct
resource object to pass to devm_of_iomap() is needed and for this the
pointer to a struct platform_device object corresponding to the node we
look for in the loop is needed. So, I think this cannot be done this way.

> 
>> Reported-by: kernel test robot <lkp@intel.com>
>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>> ---
>>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>>   1 file changed, 20 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/power/reset/at91-reset.c
>> b/drivers/power/reset/at91-reset.c
>> index 3ff9d93a5226..2ff7833153b6 100644
>> --- a/drivers/power/reset/at91-reset.c
>> +++ b/drivers/power/reset/at91-reset.c
>> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct
>> platform_device *pdev)
>>               if (!reset->ramc_base[idx]) {
>>                   dev_err(&pdev->dev, "Could not map ram controller
>> address\n");
>>                   of_node_put(np);
>> -                return -ENODEV;
>> +                ret = -ENODEV;
>> +                goto unmap;
>>               }
>>               idx++;
>>           }
>> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct
>> platform_device *pdev)
>>       reset->args = (u32)match->data;
>>         reset->sclk = devm_clk_get(&pdev->dev, NULL);
>> -    if (IS_ERR(reset->sclk))
>> -        return PTR_ERR(reset->sclk);
>> +    if (IS_ERR(reset->sclk)) {
>> +        ret = PTR_ERR(reset->sclk);
>> +        goto unmap;
>> +    }
>>         ret = clk_prepare_enable(reset->sclk);
>>       if (ret) {
>>           dev_err(&pdev->dev, "Could not enable slow clock\n");
>> -        return ret;
>> +        goto unmap;
>>       }
>>         platform_set_drvdata(pdev, reset);
>> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct
>> platform_device *pdev)
>>       ret = register_restart_handler(&reset->nb);
>>       if (ret) {
>>           clk_disable_unprepare(reset->sclk);
>> -        return ret;
>> +        goto unmap;
>>       }
>>         at91_reset_status(pdev, reset->rstc_base);
>>         return 0;
>> +
>> +unmap:
>> +    iounmap(reset->rstc_base);
>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>> +        iounmap(reset->ramc_base[idx]);
> 
> But if we keep this loop, I have the feeling that some kind of
> "of_node_put()" is needed as well.

No! In the loop:

for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
	reset->ramc_lpr = (u32)match->data;
	reset->ramc_base[idx] = of_iomap(np, 0);
	if (!reset->ramc_base[idx]) {
		dev_err(&pdev->dev, "Could not map ram controller address\n");
		of_node_put(np);
		ret = -ENODEV;
		goto unmap;
	}
	idx++;
}

the of_node_put() is needed only if the loop is interrupted as the macro:
for_each_matching_node_and_match() is defined as follows:

#define for_each_matching_node_and_match(dn, matches, match) \
	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
	     dn; dn = of_find_matching_node_and_match(dn, matches, match))

and of_find_matching_node_and_match() will return a np with refcount
incremented but at the next loop step the of_find_matching_node_and_match()
will be called with the same np pointer and the np refcount will be
decremented.

struct device_node *of_find_matching_node_and_match(
		struct device_node *from,
		const struct of_device_id *matches,
		const struct of_device_id **match)
{
	// ...
	of_node_put(from);
	// ...
}

> 
>> +
>> +    return ret;
>>   }
>>     static int __exit at91_reset_remove(struct platform_device *pdev)
>>   {
>>       struct at91_reset *reset = platform_get_drvdata(pdev);
>> +    int idx;
>>         unregister_restart_handler(&reset->nb);
>>       clk_disable_unprepare(reset->sclk);
>>   +    iounmap(reset->rstc_base);
>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>> +        iounmap(reset->ramc_base[idx]);
> 
> Ditto
> 
>> +
>>       return 0;
>>   }
>>  
> 
> 

Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Claudiu.Beznea]

On 31.03.2021 11:18, Nicolas Ferre wrote:
> On 09/02/2021 at 12:01, Claudiu Beznea wrote:
>> Free resources on exit path (failure path of probe and remove).
> 
> I'm not sure we can use this driver as a module anyway.
> 
> Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(),
> even in loop, and avoid having to deal with exit path?

For:
reset->rstc_base = of_iomap(pdev->dev.of_node, 0);

it should work.

For the maps in the loop I have to double check. Basically, the struct
resource object to pass to devm_of_iomap() is needed and for this the
pointer to a struct platform_device object corresponding to the node we
look for in the loop is needed. So, I think this cannot be done this way.

> 
>> Reported-by: kernel test robot <lkp@intel.com>
>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>> ---
>>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>>   1 file changed, 20 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/power/reset/at91-reset.c
>> b/drivers/power/reset/at91-reset.c
>> index 3ff9d93a5226..2ff7833153b6 100644
>> --- a/drivers/power/reset/at91-reset.c
>> +++ b/drivers/power/reset/at91-reset.c
>> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct
>> platform_device *pdev)
>>               if (!reset->ramc_base[idx]) {
>>                   dev_err(&pdev->dev, "Could not map ram controller
>> address\n");
>>                   of_node_put(np);
>> -                return -ENODEV;
>> +                ret = -ENODEV;
>> +                goto unmap;
>>               }
>>               idx++;
>>           }
>> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct
>> platform_device *pdev)
>>       reset->args = (u32)match->data;
>>         reset->sclk = devm_clk_get(&pdev->dev, NULL);
>> -    if (IS_ERR(reset->sclk))
>> -        return PTR_ERR(reset->sclk);
>> +    if (IS_ERR(reset->sclk)) {
>> +        ret = PTR_ERR(reset->sclk);
>> +        goto unmap;
>> +    }
>>         ret = clk_prepare_enable(reset->sclk);
>>       if (ret) {
>>           dev_err(&pdev->dev, "Could not enable slow clock\n");
>> -        return ret;
>> +        goto unmap;
>>       }
>>         platform_set_drvdata(pdev, reset);
>> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct
>> platform_device *pdev)
>>       ret = register_restart_handler(&reset->nb);
>>       if (ret) {
>>           clk_disable_unprepare(reset->sclk);
>> -        return ret;
>> +        goto unmap;
>>       }
>>         at91_reset_status(pdev, reset->rstc_base);
>>         return 0;
>> +
>> +unmap:
>> +    iounmap(reset->rstc_base);
>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>> +        iounmap(reset->ramc_base[idx]);
> 
> But if we keep this loop, I have the feeling that some kind of
> "of_node_put()" is needed as well.

No! In the loop:

for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
	reset->ramc_lpr = (u32)match->data;
	reset->ramc_base[idx] = of_iomap(np, 0);
	if (!reset->ramc_base[idx]) {
		dev_err(&pdev->dev, "Could not map ram controller address\n");
		of_node_put(np);
		ret = -ENODEV;
		goto unmap;
	}
	idx++;
}

the of_node_put() is needed only if the loop is interrupted as the macro:
for_each_matching_node_and_match() is defined as follows:

#define for_each_matching_node_and_match(dn, matches, match) \
	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
	     dn; dn = of_find_matching_node_and_match(dn, matches, match))

and of_find_matching_node_and_match() will return a np with refcount
incremented but at the next loop step the of_find_matching_node_and_match()
will be called with the same np pointer and the np refcount will be
decremented.

struct device_node *of_find_matching_node_and_match(
		struct device_node *from,
		const struct of_device_id *matches,
		const struct of_device_id **match)
{
	// ...
	of_node_put(from);
	// ...
}

> 
>> +
>> +    return ret;
>>   }
>>     static int __exit at91_reset_remove(struct platform_device *pdev)
>>   {
>>       struct at91_reset *reset = platform_get_drvdata(pdev);
>> +    int idx;
>>         unregister_restart_handler(&reset->nb);
>>       clk_disable_unprepare(reset->sclk);
>>   +    iounmap(reset->rstc_base);
>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>> +        iounmap(reset->ramc_base[idx]);
> 
> Ditto
> 
>> +
>>       return 0;
>>   }
>>  
> 
> 


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Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Claudiu.Beznea]

On 01.04.2021 17:42, Claudiu Beznea - M18063 wrote:
> On 31.03.2021 11:18, Nicolas Ferre wrote:
>> On 09/02/2021 at 12:01, Claudiu Beznea wrote:
>>> Free resources on exit path (failure path of probe and remove).
>>
>> I'm not sure we can use this driver as a module anyway.
>>
>> Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(),
>> even in loop, and avoid having to deal with exit path?
> 
> For:
> reset->rstc_base = of_iomap(pdev->dev.of_node, 0);
> 
> it should work.
> 
> For the maps in the loop I have to double check. Basically, the struct
> resource object to pass to devm_of_iomap() is needed and for this the

Just realized I looked at the wrong code. Anyway, I'll double check and return.

> pointer to a struct platform_device object corresponding to the node we
> look for in the loop is needed. So, I think this cannot be done this way.
> 
>>
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>>> ---
>>>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>>>   1 file changed, 20 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/power/reset/at91-reset.c
>>> b/drivers/power/reset/at91-reset.c
>>> index 3ff9d93a5226..2ff7833153b6 100644
>>> --- a/drivers/power/reset/at91-reset.c
>>> +++ b/drivers/power/reset/at91-reset.c
>>> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>>               if (!reset->ramc_base[idx]) {
>>>                   dev_err(&pdev->dev, "Could not map ram controller
>>> address\n");
>>>                   of_node_put(np);
>>> -                return -ENODEV;
>>> +                ret = -ENODEV;
>>> +                goto unmap;
>>>               }
>>>               idx++;
>>>           }
>>> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>>       reset->args = (u32)match->data;
>>>         reset->sclk = devm_clk_get(&pdev->dev, NULL);
>>> -    if (IS_ERR(reset->sclk))
>>> -        return PTR_ERR(reset->sclk);
>>> +    if (IS_ERR(reset->sclk)) {
>>> +        ret = PTR_ERR(reset->sclk);
>>> +        goto unmap;
>>> +    }
>>>         ret = clk_prepare_enable(reset->sclk);
>>>       if (ret) {
>>>           dev_err(&pdev->dev, "Could not enable slow clock\n");
>>> -        return ret;
>>> +        goto unmap;
>>>       }
>>>         platform_set_drvdata(pdev, reset);
>>> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>>       ret = register_restart_handler(&reset->nb);
>>>       if (ret) {
>>>           clk_disable_unprepare(reset->sclk);
>>> -        return ret;
>>> +        goto unmap;
>>>       }
>>>         at91_reset_status(pdev, reset->rstc_base);
>>>         return 0;
>>> +
>>> +unmap:
>>> +    iounmap(reset->rstc_base);
>>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> +        iounmap(reset->ramc_base[idx]);
>>
>> But if we keep this loop, I have the feeling that some kind of
>> "of_node_put()" is needed as well.
> 
> No! In the loop:
> 
> for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
> 	reset->ramc_lpr = (u32)match->data;
> 	reset->ramc_base[idx] = of_iomap(np, 0);
> 	if (!reset->ramc_base[idx]) {
> 		dev_err(&pdev->dev, "Could not map ram controller address\n");
> 		of_node_put(np);
> 		ret = -ENODEV;
> 		goto unmap;
> 	}
> 	idx++;
> }
> 
> the of_node_put() is needed only if the loop is interrupted as the macro:
> for_each_matching_node_and_match() is defined as follows:
> 
> #define for_each_matching_node_and_match(dn, matches, match) \
> 	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
> 	     dn; dn = of_find_matching_node_and_match(dn, matches, match))
> 
> and of_find_matching_node_and_match() will return a np with refcount
> incremented but at the next loop step the of_find_matching_node_and_match()
> will be called with the same np pointer and the np refcount will be
> decremented.
> 
> struct device_node *of_find_matching_node_and_match(
> 		struct device_node *from,
> 		const struct of_device_id *matches,
> 		const struct of_device_id **match)
> {
> 	// ...
> 	of_node_put(from);
> 	// ...
> }
> 
>>
>>> +
>>> +    return ret;
>>>   }
>>>     static int __exit at91_reset_remove(struct platform_device *pdev)
>>>   {
>>>       struct at91_reset *reset = platform_get_drvdata(pdev);
>>> +    int idx;
>>>         unregister_restart_handler(&reset->nb);
>>>       clk_disable_unprepare(reset->sclk);
>>>   +    iounmap(reset->rstc_base);
>>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> +        iounmap(reset->ramc_base[idx]);
>>
>> Ditto
>>
>>> +
>>>       return 0;
>>>   }
>>>  
>>
>>
> 

Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Claudiu.Beznea]

On 01.04.2021 17:42, Claudiu Beznea - M18063 wrote:
> On 31.03.2021 11:18, Nicolas Ferre wrote:
>> On 09/02/2021 at 12:01, Claudiu Beznea wrote:
>>> Free resources on exit path (failure path of probe and remove).
>>
>> I'm not sure we can use this driver as a module anyway.
>>
>> Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(),
>> even in loop, and avoid having to deal with exit path?
> 
> For:
> reset->rstc_base = of_iomap(pdev->dev.of_node, 0);
> 
> it should work.
> 
> For the maps in the loop I have to double check. Basically, the struct
> resource object to pass to devm_of_iomap() is needed and for this the

Just realized I looked at the wrong code. Anyway, I'll double check and return.

> pointer to a struct platform_device object corresponding to the node we
> look for in the loop is needed. So, I think this cannot be done this way.
> 
>>
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>>> ---
>>>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>>>   1 file changed, 20 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/power/reset/at91-reset.c
>>> b/drivers/power/reset/at91-reset.c
>>> index 3ff9d93a5226..2ff7833153b6 100644
>>> --- a/drivers/power/reset/at91-reset.c
>>> +++ b/drivers/power/reset/at91-reset.c
>>> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>>               if (!reset->ramc_base[idx]) {
>>>                   dev_err(&pdev->dev, "Could not map ram controller
>>> address\n");
>>>                   of_node_put(np);
>>> -                return -ENODEV;
>>> +                ret = -ENODEV;
>>> +                goto unmap;
>>>               }
>>>               idx++;
>>>           }
>>> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>>       reset->args = (u32)match->data;
>>>         reset->sclk = devm_clk_get(&pdev->dev, NULL);
>>> -    if (IS_ERR(reset->sclk))
>>> -        return PTR_ERR(reset->sclk);
>>> +    if (IS_ERR(reset->sclk)) {
>>> +        ret = PTR_ERR(reset->sclk);
>>> +        goto unmap;
>>> +    }
>>>         ret = clk_prepare_enable(reset->sclk);
>>>       if (ret) {
>>>           dev_err(&pdev->dev, "Could not enable slow clock\n");
>>> -        return ret;
>>> +        goto unmap;
>>>       }
>>>         platform_set_drvdata(pdev, reset);
>>> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct
>>> platform_device *pdev)
>>>       ret = register_restart_handler(&reset->nb);
>>>       if (ret) {
>>>           clk_disable_unprepare(reset->sclk);
>>> -        return ret;
>>> +        goto unmap;
>>>       }
>>>         at91_reset_status(pdev, reset->rstc_base);
>>>         return 0;
>>> +
>>> +unmap:
>>> +    iounmap(reset->rstc_base);
>>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> +        iounmap(reset->ramc_base[idx]);
>>
>> But if we keep this loop, I have the feeling that some kind of
>> "of_node_put()" is needed as well.
> 
> No! In the loop:
> 
> for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
> 	reset->ramc_lpr = (u32)match->data;
> 	reset->ramc_base[idx] = of_iomap(np, 0);
> 	if (!reset->ramc_base[idx]) {
> 		dev_err(&pdev->dev, "Could not map ram controller address\n");
> 		of_node_put(np);
> 		ret = -ENODEV;
> 		goto unmap;
> 	}
> 	idx++;
> }
> 
> the of_node_put() is needed only if the loop is interrupted as the macro:
> for_each_matching_node_and_match() is defined as follows:
> 
> #define for_each_matching_node_and_match(dn, matches, match) \
> 	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
> 	     dn; dn = of_find_matching_node_and_match(dn, matches, match))
> 
> and of_find_matching_node_and_match() will return a np with refcount
> incremented but at the next loop step the of_find_matching_node_and_match()
> will be called with the same np pointer and the np refcount will be
> decremented.
> 
> struct device_node *of_find_matching_node_and_match(
> 		struct device_node *from,
> 		const struct of_device_id *matches,
> 		const struct of_device_id **match)
> {
> 	// ...
> 	of_node_put(from);
> 	// ...
> }
> 
>>
>>> +
>>> +    return ret;
>>>   }
>>>     static int __exit at91_reset_remove(struct platform_device *pdev)
>>>   {
>>>       struct at91_reset *reset = platform_get_drvdata(pdev);
>>> +    int idx;
>>>         unregister_restart_handler(&reset->nb);
>>>       clk_disable_unprepare(reset->sclk);
>>>   +    iounmap(reset->rstc_base);
>>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> +        iounmap(reset->ramc_base[idx]);
>>
>> Ditto
>>
>>> +
>>>       return 0;
>>>   }
>>>  
>>
>>
> 


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Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Nicolas Ferre]

On 01/04/2021 at 16:42, Claudiu Beznea - M18063 wrote:
>>> +unmap:
>>> +    iounmap(reset->rstc_base);
>>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> +        iounmap(reset->ramc_base[idx]);
>> But if we keep this loop, I have the feeling that some kind of
>> "of_node_put()" is needed as well.
> No! In the loop:
> 
> for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
> 	reset->ramc_lpr = (u32)match->data;
> 	reset->ramc_base[idx] = of_iomap(np, 0);
> 	if (!reset->ramc_base[idx]) {
> 		dev_err(&pdev->dev, "Could not map ram controller address\n");
> 		of_node_put(np);
> 		ret = -ENODEV;
> 		goto unmap;
> 	}
> 	idx++;
> }
> 
> the of_node_put() is needed only if the loop is interrupted as the macro:
> for_each_matching_node_and_match() is defined as follows:
> 
> #define for_each_matching_node_and_match(dn, matches, match) \
> 	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
> 	     dn; dn = of_find_matching_node_and_match(dn, matches, match))
> 
> and of_find_matching_node_and_match() will return a np with refcount
> incremented but at the next loop step the of_find_matching_node_and_match()
> will be called with the same np pointer and the np refcount will be
> decremented.
> 
> struct device_node *of_find_matching_node_and_match(
> 		struct device_node *from,
> 		const struct of_device_id *matches,
> 		const struct of_device_id **match)
> {
> 	// ...
> 	of_node_put(from);
> 	// ...
> }

Oh yes you're right Claudiu, I overlooked this one. Thanks for the 
in-depth explanation.

Best regards,
   Nicolas

-- 
Nicolas Ferre

Re: [PATCH] power: reset: at91-reset: free resources on exit path

[Nicolas Ferre]

On 01/04/2021 at 16:42, Claudiu Beznea - M18063 wrote:
>>> +unmap:
>>> +    iounmap(reset->rstc_base);
>>> +    for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
>>> +        iounmap(reset->ramc_base[idx]);
>> But if we keep this loop, I have the feeling that some kind of
>> "of_node_put()" is needed as well.
> No! In the loop:
> 
> for_each_matching_node_and_match(np, at91_ramc_of_match, &match) {
> 	reset->ramc_lpr = (u32)match->data;
> 	reset->ramc_base[idx] = of_iomap(np, 0);
> 	if (!reset->ramc_base[idx]) {
> 		dev_err(&pdev->dev, "Could not map ram controller address\n");
> 		of_node_put(np);
> 		ret = -ENODEV;
> 		goto unmap;
> 	}
> 	idx++;
> }
> 
> the of_node_put() is needed only if the loop is interrupted as the macro:
> for_each_matching_node_and_match() is defined as follows:
> 
> #define for_each_matching_node_and_match(dn, matches, match) \
> 	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
> 	     dn; dn = of_find_matching_node_and_match(dn, matches, match))
> 
> and of_find_matching_node_and_match() will return a np with refcount
> incremented but at the next loop step the of_find_matching_node_and_match()
> will be called with the same np pointer and the np refcount will be
> decremented.
> 
> struct device_node *of_find_matching_node_and_match(
> 		struct device_node *from,
> 		const struct of_device_id *matches,
> 		const struct of_device_id **match)
> {
> 	// ...
> 	of_node_put(from);
> 	// ...
> }

Oh yes you're right Claudiu, I overlooked this one. Thanks for the 
in-depth explanation.

Best regards,
   Nicolas

-- 
Nicolas Ferre

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