Re: [PATCH 2/2] ASoC: dapm: Adapt for debugfs API change

[Greg KH <greg@kroah.com>]

On Fri, Jun 21, 2019 at 12:33:57PM +0100, Mark Brown wrote:
> Back in ff9fb72bc07705c (debugfs: return error values, not NULL) the
> debugfs APIs were changed to return error pointers rather than NULL
> pointers on error, breaking the error checking in ASoC. Update the
> code to use IS_ERR() and log the codes that are returned as part of
> the error messages.
> 
> Fixes: ff9fb72bc07705c (debugfs: return error values, not NULL)
> Signed-off-by: Mark Brown <broonie@kernel.org>
> Cc: stable@vger.kernel.org
> ---
>  sound/soc/soc-dapm.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
> index 6b44b4a78b8e..f013b24c050a 100644
> --- a/sound/soc/soc-dapm.c
> +++ b/sound/soc/soc-dapm.c
> @@ -2156,23 +2156,25 @@ void snd_soc_dapm_debugfs_init(struct snd_soc_dapm_context *dapm,
>  {
>  	struct dentry *d;
>  
> -	if (!parent)
> +	if (!parent || IS_ERR(parent))
>  		return;

How can parent be NULL?

>  
>  	dapm->debugfs_dapm = debugfs_create_dir("dapm", parent);
>  
> -	if (!dapm->debugfs_dapm) {
> +	if (IS_ERR(dapm->debugfs_dapm)) {
>  		dev_warn(dapm->dev,
> -		       "ASoC: Failed to create DAPM debugfs directory\n");
> +			 "ASoC: Failed to create DAPM debugfs directory %ld\n",
> +			 PTR_ERR(dapm->debugfs_dapm));

Same comment as before, no need to print anything.

>  		return;
>  	}
>  
>  	d = debugfs_create_file("bias_level", 0444,
>  				dapm->debugfs_dapm, dapm,
>  				&dapm_bias_fops);
> -	if (!d)
> +	if (IS_ERR(d))
>  		dev_warn(dapm->dev,
> -			 "ASoC: Failed to create bias level debugfs file\n");
> +			 "ASoC: Failed to create bias level debugfs file: %ld\n",
> +			 PTR_ERR(d));

Again, no need to warn, no one will see it :)

I am trying to make it so that debugfs doesn't return anything for when
a file is created.  Now if that will ever be possible or not, I don't
know, but I am pretty close in one of the branches in my driver-core
tree...

thanks,

greg k-h