[PATCH 1/1] ath11k: fix return value check in ath11k_spectral_debug_register()

[Jeff Johnson]

On 10/23/2024 12:40 AM, Zhen Lei wrote:
> Fix the incorrect return value check for debugfs_create_file(), which
> returns ERR_PTR(-ERROR) instead of NULL when it fails.

Based upon the commit text this change is incorrect.

 * NOTE: it's expected that most callers should _ignore_ the errors returned
 * by this function. Other debugfs functions handle the fact that the "dentry"
 * passed to them could be an error and they don't crash in that case.
 * Drivers should generally work fine even if debugfs fails to init anyway.

So ath11k should not be checking the return value at all, and definitely
should not be returning -EINVAL since the driver should still operate even if
creating a debugfs file fails.

> 
> Fixes: 9d11b7bff950 ("ath11k: add support for spectral scan")
> Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>
> ---
>  drivers/net/wireless/ath/ath11k/spectral.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/spectral.c b/drivers/net/wireless/ath/ath11k/spectral.c
> index 79e091134515b43..4c545231292142a 100644
> --- a/drivers/net/wireless/ath/ath11k/spectral.c
> +++ b/drivers/net/wireless/ath/ath11k/spectral.c
> @@ -942,7 +942,7 @@ static inline int ath11k_spectral_debug_register(struct ath11k *ar)
>  						    0600,
>  						    ar->debug.debugfs_pdev, ar,
>  						    &fops_scan_ctl);
> -	if (!ar->spectral.scan_ctl) {
> +	if (IS_ERR(ar->spectral.scan_ctl)) {
>  		ath11k_warn(ar->ab, "failed to open debugfs in pdev %d\n",
>  			    ar->pdev_idx);
>  		ret = -EINVAL;
> @@ -953,7 +953,7 @@ static inline int ath11k_spectral_debug_register(struct ath11k *ar)
>  						      0600,
>  						      ar->debug.debugfs_pdev, ar,
>  						      &fops_scan_count);
> -	if (!ar->spectral.scan_count) {
> +	if (IS_ERR(ar->spectral.scan_count)) {
>  		ath11k_warn(ar->ab, "failed to open debugfs in pdev %d\n",
>  			    ar->pdev_idx);
>  		ret = -EINVAL;
> @@ -964,7 +964,7 @@ static inline int ath11k_spectral_debug_register(struct ath11k *ar)
>  						     0600,
>  						     ar->debug.debugfs_pdev, ar,
>  						     &fops_scan_bins);
> -	if (!ar->spectral.scan_bins) {
> +	if (IS_ERR(ar->spectral.scan_bins)) {
>  		ath11k_warn(ar->ab, "failed to open debugfs in pdev %d\n",
>  			    ar->pdev_idx);
>  		ret = -EINVAL;