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* [PATCH] Input: davinci_keyscan: Free memory occupied by davinci key scan device
@ 2017-11-14 13:45 Arvind Yadav
  2017-11-14 18:14 ` Dmitry Torokhov
  0 siblings, 1 reply; 3+ messages in thread
From: Arvind Yadav @ 2017-11-14 13:45 UTC (permalink / raw)
  To: dmitry.torokhov, linux; +Cc: linux-kernel, linux-input

Here, key_dev is NULL in input_free_device() and It will not free
memory occupied by davinci key scan device. Move "key_dev = NULL"
after input_free_device().

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
---
 drivers/input/keyboard/davinci_keyscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/davinci_keyscan.c b/drivers/input/keyboard/davinci_keyscan.c
index b20a5d0..22cb8d2 100644
--- a/drivers/input/keyboard/davinci_keyscan.c
+++ b/drivers/input/keyboard/davinci_keyscan.c
@@ -290,13 +290,13 @@ static int __init davinci_ks_probe(struct platform_device *pdev)
 	free_irq(davinci_ks->irq, davinci_ks);
 fail5:
 	input_unregister_device(davinci_ks->input);
-	key_dev = NULL;
 fail4:
 	iounmap(davinci_ks->base);
 fail3:
 	release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
 fail2:
 	input_free_device(key_dev);
+	key_dev = NULL;
 fail1:
 	kfree(davinci_ks);
 
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] Input: davinci_keyscan: Free memory occupied by davinci key scan device
  2017-11-14 13:45 [PATCH] Input: davinci_keyscan: Free memory occupied by davinci key scan device Arvind Yadav
@ 2017-11-14 18:14 ` Dmitry Torokhov
  2017-11-14 18:40   ` arvindY
  0 siblings, 1 reply; 3+ messages in thread
From: Dmitry Torokhov @ 2017-11-14 18:14 UTC (permalink / raw)
  To: Arvind Yadav; +Cc: linux, linux-kernel, linux-input

On Tue, Nov 14, 2017 at 07:15:14PM +0530, Arvind Yadav wrote:
> Here, key_dev is NULL in input_free_device() and It will not free
> memory occupied by davinci key scan device. Move "key_dev = NULL"
> after input_free_device().

No, this is absolutely wrong. It is disallowed to call
input_free_device() after calling input_unregister_device(), because
input core will free the device once the last reference is dropped. That
is why we set "key_dev" to NULL to turn input_free_device() into a noop.

> 
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
> ---
>  drivers/input/keyboard/davinci_keyscan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/input/keyboard/davinci_keyscan.c b/drivers/input/keyboard/davinci_keyscan.c
> index b20a5d0..22cb8d2 100644
> --- a/drivers/input/keyboard/davinci_keyscan.c
> +++ b/drivers/input/keyboard/davinci_keyscan.c
> @@ -290,13 +290,13 @@ static int __init davinci_ks_probe(struct platform_device *pdev)
>  	free_irq(davinci_ks->irq, davinci_ks);
>  fail5:
>  	input_unregister_device(davinci_ks->input);
> -	key_dev = NULL;
>  fail4:
>  	iounmap(davinci_ks->base);
>  fail3:
>  	release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
>  fail2:
>  	input_free_device(key_dev);
> +	key_dev = NULL;
>  fail1:
>  	kfree(davinci_ks);
>  
> -- 
> 1.9.1
> 

Thanks.

-- 
Dmitry

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] Input: davinci_keyscan: Free memory occupied by davinci key scan device
  2017-11-14 18:14 ` Dmitry Torokhov
@ 2017-11-14 18:40   ` arvindY
  0 siblings, 0 replies; 3+ messages in thread
From: arvindY @ 2017-11-14 18:40 UTC (permalink / raw)
  To: Dmitry Torokhov; +Cc: linux, linux-kernel, linux-input



On Tuesday 14 November 2017 11:44 PM, Dmitry Torokhov wrote:
> On Tue, Nov 14, 2017 at 07:15:14PM +0530, Arvind Yadav wrote:
>> Here, key_dev is NULL in input_free_device() and It will not free
>> memory occupied by davinci key scan device. Move "key_dev = NULL"
>> after input_free_device().
> No, this is absolutely wrong. It is disallowed to call
> input_free_device() after calling input_unregister_device(), because
> input core will free the device once the last reference is dropped. That
> is why we set "key_dev" to NULL to turn input_free_device() into a noop.
Yes, You are correct. Once device is unregistered it will get freed.

Thanks, :)
>> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
>> ---
>>   drivers/input/keyboard/davinci_keyscan.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/input/keyboard/davinci_keyscan.c b/drivers/input/keyboard/davinci_keyscan.c
>> index b20a5d0..22cb8d2 100644
>> --- a/drivers/input/keyboard/davinci_keyscan.c
>> +++ b/drivers/input/keyboard/davinci_keyscan.c
>> @@ -290,13 +290,13 @@ static int __init davinci_ks_probe(struct platform_device *pdev)
>>   	free_irq(davinci_ks->irq, davinci_ks);
>>   fail5:
>>   	input_unregister_device(davinci_ks->input);
>> -	key_dev = NULL;
>>   fail4:
>>   	iounmap(davinci_ks->base);
>>   fail3:
>>   	release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
>>   fail2:
>>   	input_free_device(key_dev);
>> +	key_dev = NULL;
>>   fail1:
>>   	kfree(davinci_ks);
>>   
>> -- 
>> 1.9.1
>>
> Thanks.
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2017-11-14 18:40 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2017-11-14 13:45 [PATCH] Input: davinci_keyscan: Free memory occupied by davinci key scan device Arvind Yadav
2017-11-14 18:14 ` Dmitry Torokhov
2017-11-14 18:40   ` arvindY

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