linux-kernel - Re: [PATCH] mic: no need to check return value of debugfs

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Date:   Wed, 12 Jun 2019 08:41:27 -0700
From:   Sudeep Dutt <sudeep.dutt@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Sudeep Dutt <sudeep.dutt@...el.com>,
        Ashutosh Dixit <ashutosh.dixit@...el.com>,
        Arnd Bergmann <arnd@...db.de>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mic: no need to check return value of debugfs_create
 functions

On Tue, 2019-06-11 at 20:43 +0200, Greg Kroah-Hartman wrote:
> When calling debugfs functions, there is no need to ever check the
> return value.  The function can work or not, but the code logic should
> never do something different based on this.
> 

Thanks Greg.

Reviewed-by: Sudeep Dutt <sudeep.dutt@...el.com>

> Cc: Sudeep Dutt <sudeep.dutt@...el.com>
> Cc: Ashutosh Dixit <ashutosh.dixit@...el.com>
> Cc: Arnd Bergmann <arnd@...db.de>
> Cc: linux-kernel@...r.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> ---
>  drivers/misc/mic/card/mic_debugfs.c  | 18 ++----------------
>  drivers/misc/mic/cosm/cosm_debugfs.c |  4 ----
>  drivers/misc/mic/host/mic_debugfs.c  |  4 ----
>  drivers/misc/mic/scif/scif_debugfs.c |  5 -----
>  drivers/misc/mic/vop/vop_debugfs.c   |  4 ----
>  5 files changed, 2 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/misc/mic/card/mic_debugfs.c b/drivers/misc/mic/card/mic_debugfs.c
> index 7a4140874888..fa2b5fefb791 100644
> --- a/drivers/misc/mic/card/mic_debugfs.c
> +++ b/drivers/misc/mic/card/mic_debugfs.c
> @@ -63,25 +63,13 @@ DEFINE_SHOW_ATTRIBUTE(mic_intr);
>   */
>  void __init mic_create_card_debug_dir(struct mic_driver *mdrv)
>  {
> -	struct dentry *d;
> -
>  	if (!mic_dbg)
>  		return;
>  
>  	mdrv->dbg_dir = debugfs_create_dir(mdrv->name, mic_dbg);
> -	if (!mdrv->dbg_dir) {
> -		dev_err(mdrv->dev, "Cant create dbg_dir %s\n", mdrv->name);
> -		return;
> -	}
> -
> -	d = debugfs_create_file("intr_test", 0444, mdrv->dbg_dir,
> -		mdrv, &mic_intr_fops);
>  
> -	if (!d) {
> -		dev_err(mdrv->dev,
> -			"Cant create dbg intr_test %s\n", mdrv->name);
> -		return;
> -	}
> +	debugfs_create_file("intr_test", 0444, mdrv->dbg_dir, mdrv,
> +			    &mic_intr_fops);
>  }
>  
>  /**
> @@ -101,8 +89,6 @@ void mic_delete_card_debug_dir(struct mic_driver *mdrv)
>  void __init mic_init_card_debugfs(void)
>  {
>  	mic_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
> -	if (!mic_dbg)
> -		pr_err("can't create debugfs dir\n");
>  }
>  
>  /**
> diff --git a/drivers/misc/mic/cosm/cosm_debugfs.c b/drivers/misc/mic/cosm/cosm_debugfs.c
> index 71c216d0504d..340ea7171411 100644
> --- a/drivers/misc/mic/cosm/cosm_debugfs.c
> +++ b/drivers/misc/mic/cosm/cosm_debugfs.c
> @@ -105,8 +105,6 @@ void cosm_create_debug_dir(struct cosm_device *cdev)
>  
>  	scnprintf(name, sizeof(name), "mic%d", cdev->index);
>  	cdev->dbg_dir = debugfs_create_dir(name, cosm_dbg);
> -	if (!cdev->dbg_dir)
> -		return;
>  
>  	debugfs_create_file("log_buf", 0444, cdev->dbg_dir, cdev,
>  			    &log_buf_fops);
> @@ -125,8 +123,6 @@ void cosm_delete_debug_dir(struct cosm_device *cdev)
>  void cosm_init_debugfs(void)
>  {
>  	cosm_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
> -	if (!cosm_dbg)
> -		pr_err("can't create debugfs dir\n");
>  }
>  
>  void cosm_exit_debugfs(void)
> diff --git a/drivers/misc/mic/host/mic_debugfs.c b/drivers/misc/mic/host/mic_debugfs.c
> index c6e3c764699f..370f98c7b752 100644
> --- a/drivers/misc/mic/host/mic_debugfs.c
> +++ b/drivers/misc/mic/host/mic_debugfs.c
> @@ -125,8 +125,6 @@ void mic_create_debug_dir(struct mic_device *mdev)
>  
>  	scnprintf(name, sizeof(name), "mic%d", mdev->id);
>  	mdev->dbg_dir = debugfs_create_dir(name, mic_dbg);
> -	if (!mdev->dbg_dir)
> -		return;
>  
>  	debugfs_create_file("smpt", 0444, mdev->dbg_dir, mdev,
>  			    &mic_smpt_fops);
> @@ -155,8 +153,6 @@ void mic_delete_debug_dir(struct mic_device *mdev)
>  void __init mic_init_debugfs(void)
>  {
>  	mic_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
> -	if (!mic_dbg)
> -		pr_err("can't create debugfs dir\n");
>  }
>  
>  /**
> diff --git a/drivers/misc/mic/scif/scif_debugfs.c b/drivers/misc/mic/scif/scif_debugfs.c
> index a6820480105a..8fe38e7ca6e6 100644
> --- a/drivers/misc/mic/scif/scif_debugfs.c
> +++ b/drivers/misc/mic/scif/scif_debugfs.c
> @@ -103,11 +103,6 @@ DEFINE_SHOW_ATTRIBUTE(scif_rma);
>  void __init scif_init_debugfs(void)
>  {
>  	scif_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
> -	if (!scif_dbg) {
> -		dev_err(scif_info.mdev.this_device,
> -			"can't create debugfs dir scif\n");
> -		return;
> -	}
>  
>  	debugfs_create_file("scif_dev", 0444, scif_dbg, NULL, &scif_dev_fops);
>  	debugfs_create_file("scif_rma", 0444, scif_dbg, NULL, &scif_rma_fops);
> diff --git a/drivers/misc/mic/vop/vop_debugfs.c b/drivers/misc/mic/vop/vop_debugfs.c
> index 2ccef52aca23..d4551d522188 100644
> --- a/drivers/misc/mic/vop/vop_debugfs.c
> +++ b/drivers/misc/mic/vop/vop_debugfs.c
> @@ -186,10 +186,6 @@ void vop_init_debugfs(struct vop_info *vi)
>  
>  	snprintf(name, sizeof(name), "%s%d", KBUILD_MODNAME, vi->vpdev->dnode);
>  	vi->dbg = debugfs_create_dir(name, NULL);
> -	if (!vi->dbg) {
> -		pr_err("can't create debugfs dir vop\n");
> -		return;
> -	}
>  	debugfs_create_file("dp", 0444, vi->dbg, vi, &vop_dp_fops);
>  	debugfs_create_file("vdev_info", 0444, vi->dbg, vi, &vop_vdev_info_fops);
>  }