Subject: Re: [PATCH] mediatek/mt7601u: add debugfs exit function

From: Kalle Valo <[email-masked]>
Date: Fri, 22 Apr 2022 10:45:57 +0300

Bernard Zhao <[email-masked]> writes:

> When mt7601u loaded, there are two cases:
> First when mt7601u is loaded, in function mt7601u_probe, if
> function mt7601u_probe run into error lable err_hw,
> mt7601u_cleanup didn`t cleanup the debugfs node.
> Second when the module disconnect, in function mt7601u_disconnect,
> mt7601u_cleanup didn`t cleanup the debugfs node.
> This patch add debugfs exit function and try to cleanup debugfs
> node when mt7601u loaded fail or unloaded.
>
> Signed-off-by: Bernard Zhao <[email-masked]>
> ---
>  .../net/wireless/mediatek/mt7601u/debugfs.c   | 25 +++++++++++--------
>  drivers/net/wireless/mediatek/mt7601u/init.c  |  5 ++++
>  .../net/wireless/mediatek/mt7601u/mt7601u.h   |  4 +++
>  3 files changed, 24 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt7601u/debugfs.c b/drivers/net/wireless/mediatek/mt7601u/debugfs.c
> index 20669eacb66e..1ae3d75d3c9b 100644
> --- a/drivers/net/wireless/mediatek/mt7601u/debugfs.c
> +++ b/drivers/net/wireless/mediatek/mt7601u/debugfs.c
> @@ -124,17 +124,22 @@ DEFINE_SHOW_ATTRIBUTE(mt7601u_eeprom_param);
>  
>  void mt7601u_init_debugfs(struct mt7601u_dev *dev)
>  {
> -	struct dentry *dir;
> -
> -	dir = debugfs_create_dir("mt7601u", dev->hw->wiphy->debugfsdir);
> -	if (!dir)
> +	dev->root_dir = debugfs_create_dir("mt7601u", dev->hw->wiphy->debugfsdir);
> +	if (!dev->root_dir)
>  		return;
>  
> -	debugfs_create_u8("temperature", 0400, dir, &dev->raw_temp);
> -	debugfs_create_u32("temp_mode", 0400, dir, &dev->temp_mode);
> +	debugfs_create_u8("temperature", 0400, dev->root_dir, &dev->raw_temp);
> +	debugfs_create_u32("temp_mode", 0400, dev->root_dir, &dev->temp_mode);
> +
> +	debugfs_create_u32("regidx", 0600, dev->root_dir, &dev->debugfs_reg);
> +	debugfs_create_file("regval", 0600, dev->root_dir, dev, &fops_regval);
> +	debugfs_create_file("ampdu_stat", 0400, dev->root_dir, dev, &mt7601u_ampdu_stat_fops);
> +	debugfs_create_file("eeprom_param", 0400, dev->root_dir, dev, &mt7601u_eeprom_param_fops);
> +}
>  
> -	debugfs_create_u32("regidx", 0600, dir, &dev->debugfs_reg);
> -	debugfs_create_file("regval", 0600, dir, dev, &fops_regval);
> -	debugfs_create_file("ampdu_stat", 0400, dir, dev, &mt7601u_ampdu_stat_fops);
> -	debugfs_create_file("eeprom_param", 0400, dir, dev, &mt7601u_eeprom_param_fops);
> +void mt7601u_exit_debugfs(struct mt7601u_dev *dev)
> +{
> +	if (!dev->root_dir)
> +		return;
> +	debugfs_remove(dev->root_dir);

debugfs_remove() has IS_ERR_OR_NULL() check, so no need to check for
null here.

>  }
> diff --git a/drivers/net/wireless/mediatek/mt7601u/init.c b/drivers/net/wireless/mediatek/mt7601u/init.c
> index 5d9e952b2966..1e905ef2ed19 100644
> --- a/drivers/net/wireless/mediatek/mt7601u/init.c
> +++ b/drivers/net/wireless/mediatek/mt7601u/init.c
> @@ -427,6 +427,9 @@ void mt7601u_cleanup(struct mt7601u_dev *dev)
>  	mt7601u_stop_hardware(dev);
>  	mt7601u_dma_cleanup(dev);
>  	mt7601u_mcu_cmd_deinit(dev);
> +#ifdef CONFIG_DEBUG_FS
> +	mt7601u_exit_debugfs(dev);
> +#endif
>  }
>  
>  struct mt7601u_dev *mt7601u_alloc_device(struct device *pdev)
> @@ -625,7 +628,9 @@ int mt7601u_register_device(struct mt7601u_dev *dev)
>  	if (ret)
>  		return ret;
>  
> +#ifdef CONFIG_DEBUG_FS
>  	mt7601u_init_debugfs(dev);
> +#endif

Are these two ifdefs really needed? debugfs functions are empty
functions when CONFIG_DEBUG_FS is disabled.

> --- a/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
> +++ b/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
> @@ -242,6 +242,9 @@ struct mt7601u_dev {
>  	u32 rf_pa_mode[2];
>  
>  	struct mac_stats stats;
> +#ifdef CONFIG_DEBUG_FS
> +	struct dentry *root_dir;
> +#endif

I would remove this ifdef, it's just saving one pointer size. Less
ifdefs we have the better.

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