[17/22] USB: udc: atmel_usba_udc: no need to check return value of debugfs_create functions

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

Hi,

On 29/05/2018 17:31:02+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.
> 
> There is also no need to keep the file dentries around at all, so remove
> those variables from the device structure.
> 
> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> Cc: Felipe Balbi <balbi@kernel.org>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  drivers/usb/gadget/udc/atmel_usba_udc.c | 71 ++++---------------------
>  drivers/usb/gadget/udc/atmel_usba_udc.h |  4 --
>  2 files changed, 11 insertions(+), 64 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
> index 2f586f2bda7e..a4d99bf50f2f 100644
> --- a/drivers/usb/gadget/udc/atmel_usba_udc.c
> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
> @@ -206,94 +206,45 @@ static void usba_ep_init_debugfs(struct usba_udc *udc,
>  	struct dentry *ep_root;
>  
>  	ep_root = debugfs_create_dir(ep->ep.name, udc->debugfs_root);
> -	if (!ep_root)
> -		goto err_root;
>  	ep->debugfs_dir = ep_root;
>  
> -	ep->debugfs_queue = debugfs_create_file("queue", 0400, ep_root,
> -						ep, &queue_dbg_fops);
> -	if (!ep->debugfs_queue)
> -		goto err_queue;
> -
> -	if (ep->can_dma) {
> -		ep->debugfs_dma_status
> -			= debugfs_create_u32("dma_status", 0400, ep_root,
> -					&ep->last_dma_status);
> -		if (!ep->debugfs_dma_status)
> -			goto err_dma_status;
> -	}
> -	if (ep_is_control(ep)) {
> -		ep->debugfs_state
> -			= debugfs_create_u32("state", 0400, ep_root,
> -					&ep->state);
> -		if (!ep->debugfs_state)
> -			goto err_state;
> -	}
> -
> -	return;
> -
> -err_state:
> +	debugfs_create_file("queue", 0400, ep_root, ep, &queue_dbg_fops);

What happens here if debugfs_create_dir returned NULL? I guess the file
will be placed at the root of the debugfs filesystem which is not great.

Should we stop caring about that and assume that if debugfs_create_dir,
the following debugfs_create_* calls will fail?