[PATCH v2 1/2] ALSA: core: remove initialise static variables to 0

[PATCH v2 1/2] ALSA: core: remove initialise static variables to 0

[Meng Tang]

Initializing the static variable to 0 causes the following error
when exec checkpatch:

ERROR: do not initialise statics to 0
FILE: sound/sound_core.c:142:
static int preclaim_oss = 0;

In addition, considering the following way of writing
139: #ifdef config_sound_oss_core_preclaim
140: Static int preclaim_oss = 1;
141: #ELSE
142: Static int preclaim_oss = 0;
143: #ENDIF
We can optimize it by IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM),
so modified it to
static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);

Signed-off-by: Meng Tang <tangmeng@uniontech.com>
---
 sound/sound_core.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/sound/sound_core.c b/sound/sound_core.c
index 90d118cd9164..aa4a57e488e5 100644
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -136,11 +136,7 @@ struct sound_unit
  * All these clutters are scheduled to be removed along with
  * sound-slot/service-* module aliases.
  */
-#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
-static int preclaim_oss = 1;
-#else
-static int preclaim_oss = 0;
-#endif
+static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);
 
 module_param(preclaim_oss, int, 0444);
 
-- 
2.20.1

[PATCH v2 2/2] ALSA: core: Remove redundant 'err' variable

[Meng Tang]

Return the result from file->f_op->open() directly instead of
taking this in another redundant variable.

Signed-off-by: Meng Tang <tangmeng@uniontech.com>
---
 sound/sound_core.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/sound_core.c b/sound/sound_core.c
index aa4a57e488e5..3ac679ea31c7 100644
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -582,13 +582,12 @@ static int soundcore_open(struct inode *inode, struct file *file)
 		 * We rely upon the fact that we can't be unloaded while the
 		 * subdriver is there.
 		 */
-		int err = 0;
 		replace_fops(file, new_fops);
 
 		if (file->f_op->open)
-			err = file->f_op->open(inode,file);
+			return file->f_op->open(inode, file);
 
-		return err;
+		return 0;
 	}
 	return -ENODEV;
 }
-- 
2.20.1

Re: [PATCH v2 2/2] ALSA: core: Remove redundant 'err' variable

[Joe Perches]

On Mon, 2022-02-28 at 11:06 +0800, Meng Tang wrote:
> Return the result from file->f_op->open() directly instead of
> taking this in another redundant variable.
[]
> diff --git a/sound/sound_core.c b/sound/sound_core.c
[]
> @@ -582,13 +582,12 @@ static int soundcore_open(struct inode *inode, struct file *file)
>  		 * We rely upon the fact that we can't be unloaded while the
>  		 * subdriver is there.
>  		 */
> -		int err = 0;
>  		replace_fops(file, new_fops);
>  
>  		if (file->f_op->open)
> -			err = file->f_op->open(inode,file);
> +			return file->f_op->open(inode, file);
>  
> -		return err;
> +		return 0;
>  	}
>  	return -ENODEV;
>  }

Perhaps clearer would be to make the typical return the last statement,
return early and reduce the indentation too.

i.e.:

---
 sound/sound_core.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/sound/sound_core.c b/sound/sound_core.c
index 90d118cd91641..9f2cd6d91a034 100644
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -581,22 +581,20 @@ static int soundcore_open(struct inode *inode, struct file *file)
 			new_fops = fops_get(s->unit_fops);
 	}
 	spin_unlock(&sound_loader_lock);
-	if (new_fops) {
-		/*
-		 * We rely upon the fact that we can't be unloaded while the
-		 * subdriver is there.
-		 */
-		int err = 0;
-		replace_fops(file, new_fops);
+	if (!new_fops)
+		return -ENODEV;
 
-		if (file->f_op->open)
-			err = file->f_op->open(inode,file);
+	/*
+	 * We rely upon the fact that we can't be unloaded while the
+	 * subdriver is there.
+	 */
+	replace_fops(file, new_fops);
 
-		return err;
-	}
-	return -ENODEV;
-}
+	if (!file->f_op->open)
+		return -ENODEV;
 
+	return file->f_op->open(inode,file);
+}
 MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
 
 static void cleanup_oss_soundcore(void)