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[-next] ALSA: pcmtest: Drop unnecessary error check for debugfs_create_dir

Message ID 20230817063922.282746-1-ruanjinjie@huawei.com
State New
Headers show
Series [-next] ALSA: pcmtest: Drop unnecessary error check for debugfs_create_dir | expand

Commit Message

Jinjie Ruan Aug. 17, 2023, 6:39 a.m. UTC
This patch removes the error checking for debugfs_create_dir in
pcmtest.c. This is because the DebugFS kernel API is developed
in a way that the caller can safely ignore the errors that
occur during the creation of DebugFS nodes. The debugfs APIs have
a IS_ERR() judge in start_creating() which can handle it
gracefully. So these checks are unnecessary.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
---
 sound/drivers/pcmtest.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Takashi Iwai Aug. 17, 2023, 6:47 a.m. UTC | #1
On Thu, 17 Aug 2023 08:39:22 +0200,
Ruan Jinjie wrote:
> 
> This patch removes the error checking for debugfs_create_dir in
> pcmtest.c. This is because the DebugFS kernel API is developed
> in a way that the caller can safely ignore the errors that
> occur during the creation of DebugFS nodes. The debugfs APIs have
> a IS_ERR() judge in start_creating() which can handle it
> gracefully. So these checks are unnecessary.
> 
> Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>

I believe debugfs is mandatory in this case (it's a test module that
manipulates / gets notification via debugfs), hence it makes sense to
check the error.

Maybe we should add a dependency on CONFIG_DEBUG_FS in Kconfig?


thanks,

Takashi

> ---
>  sound/drivers/pcmtest.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
> index 7f170429eb8f..9360b3bb771e 100644
> --- a/sound/drivers/pcmtest.c
> +++ b/sound/drivers/pcmtest.c
> @@ -669,8 +669,6 @@ static int init_debug_files(int buf_count)
>  	char len_file_name[32];
>  
>  	driver_debug_dir = debugfs_create_dir("pcmtest", NULL);
> -	if (IS_ERR(driver_debug_dir))
> -		return PTR_ERR(driver_debug_dir);
>  	debugfs_create_u8("pc_test", 0444, driver_debug_dir, &playback_capture_test);
>  	debugfs_create_u8("ioctl_test", 0444, driver_debug_dir, &ioctl_reset_test);
>  
> -- 
> 2.34.1
>
Jinjie Ruan Aug. 17, 2023, 7:03 a.m. UTC | #2
On 2023/8/17 14:47, Takashi Iwai wrote:
> On Thu, 17 Aug 2023 08:39:22 +0200,
> Ruan Jinjie wrote:
>>
>> This patch removes the error checking for debugfs_create_dir in
>> pcmtest.c. This is because the DebugFS kernel API is developed
>> in a way that the caller can safely ignore the errors that
>> occur during the creation of DebugFS nodes. The debugfs APIs have
>> a IS_ERR() judge in start_creating() which can handle it
>> gracefully. So these checks are unnecessary.
>>
>> Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
> 
> I believe debugfs is mandatory in this case (it's a test module that
> manipulates / gets notification via debugfs), hence it makes sense to
> check the error.

So the error check is necessary!

> 
> Maybe we should add a dependency on CONFIG_DEBUG_FS in Kconfig?

I think it's ok!

> 
> 
> thanks,
> 
> Takashi
> 
>> ---
>>  sound/drivers/pcmtest.c | 2 --
>>  1 file changed, 2 deletions(-)
>>
>> diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
>> index 7f170429eb8f..9360b3bb771e 100644
>> --- a/sound/drivers/pcmtest.c
>> +++ b/sound/drivers/pcmtest.c
>> @@ -669,8 +669,6 @@ static int init_debug_files(int buf_count)
>>  	char len_file_name[32];
>>  
>>  	driver_debug_dir = debugfs_create_dir("pcmtest", NULL);
>> -	if (IS_ERR(driver_debug_dir))
>> -		return PTR_ERR(driver_debug_dir);
>>  	debugfs_create_u8("pc_test", 0444, driver_debug_dir, &playback_capture_test);
>>  	debugfs_create_u8("ioctl_test", 0444, driver_debug_dir, &ioctl_reset_test);
>>  
>> -- 
>> 2.34.1
>>
Jinjie Ruan Aug. 17, 2023, 8:33 a.m. UTC | #3
On 2023/8/17 16:30, Ivan Orlov wrote:
> On 17.08.2023 11:03, Ruan Jinjie wrote:
>> So the error check is necessary!
> 
> Yeah, it is. As Takashi already mentioned, debugfs in this case is the
> way how the driver communicates with userspace (forwards flags, receives
> filling patterns, etc.), so it is vital part of the driver.
> 
>>
>>>
>>> Maybe we should add a dependency on CONFIG_DEBUG_FS in Kconfig?
>>
>> I think it's ok!
> 
> It sounds like a great idea. Ruan, would you like to do this? If not, I
> will take it on.

Yes, I'd like to. I'll send it sooner. Thank you very much!

> 
> -- 
> Kind regards,
> Ivan Orlov
>
diff mbox series

Patch

diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
index 7f170429eb8f..9360b3bb771e 100644
--- a/sound/drivers/pcmtest.c
+++ b/sound/drivers/pcmtest.c
@@ -669,8 +669,6 @@  static int init_debug_files(int buf_count)
 	char len_file_name[32];
 
 	driver_debug_dir = debugfs_create_dir("pcmtest", NULL);
-	if (IS_ERR(driver_debug_dir))
-		return PTR_ERR(driver_debug_dir);
 	debugfs_create_u8("pc_test", 0444, driver_debug_dir, &playback_capture_test);
 	debugfs_create_u8("ioctl_test", 0444, driver_debug_dir, &ioctl_reset_test);