Re: [PATCH v3 5/5] EDAC/mc_sysfs: Begin deprecating legacy sysfs EDAC interface

[Yazen Ghannam <yazen.ghannam@amd.com>]

On Tue, Sep 09, 2025 at 06:53:14PM +0000, Avadhut Naik wrote:
> The legacy sysfs EDAC interface has been made obsolete more than a decade
> ago through the introduction of a new per-DIMM interface.
> 
> The legacy interface however, hasn't been removed till date.
> 
> Begin deprecating it so that it can eventually be removed two releases
> later.
> 
> Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
> ---
> Changes in v3:
> Patch introduced.
> ---
>  drivers/edac/Kconfig         |  2 +-
>  drivers/edac/edac_mc_sysfs.c | 14 ++++++++++++++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
> index b824472208c4..19470f4efee7 100644
> --- a/drivers/edac/Kconfig
> +++ b/drivers/edac/Kconfig
> @@ -25,7 +25,7 @@ if EDAC
>  
>  config EDAC_LEGACY_SYSFS
>  	bool "EDAC legacy sysfs"
> -	default y
> +	default n
>  	help
>  	  Enable the compatibility sysfs nodes.
>  	  Use 'Y' if your edac utilities aren't ported to work with the newer
> diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
> index 8689631f1905..3840eef942f8 100644
> --- a/drivers/edac/edac_mc_sysfs.c
> +++ b/drivers/edac/edac_mc_sysfs.c
> @@ -144,6 +144,8 @@ struct dev_ch_attribute {
>  static ssize_t csrow_ue_count_show(struct device *dev,
>  				   struct device_attribute *mattr, char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
> +
>  	struct csrow_info *csrow = to_csrow(dev);
>  
>  	return sysfs_emit(data, "%u\n", csrow->ue_count);
> @@ -152,6 +154,8 @@ static ssize_t csrow_ue_count_show(struct device *dev,
>  static ssize_t csrow_ce_count_show(struct device *dev,
>  				   struct device_attribute *mattr, char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
> +
>  	struct csrow_info *csrow = to_csrow(dev);
>  
>  	return sysfs_emit(data, "%u\n", csrow->ce_count);
> @@ -160,6 +164,8 @@ static ssize_t csrow_ce_count_show(struct device *dev,
>  static ssize_t csrow_size_show(struct device *dev,
>  			       struct device_attribute *mattr, char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
> +
>  	struct csrow_info *csrow = to_csrow(dev);
>  	int i;
>  	u32 nr_pages = 0;
> @@ -172,6 +178,8 @@ static ssize_t csrow_size_show(struct device *dev,
>  static ssize_t csrow_mem_type_show(struct device *dev,
>  				   struct device_attribute *mattr, char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
> +
>  	struct csrow_info *csrow = to_csrow(dev);
>  
>  	return sysfs_emit(data, "%s\n", edac_mem_types[csrow->channels[0]->dimm->mtype]);
> @@ -180,6 +188,8 @@ static ssize_t csrow_mem_type_show(struct device *dev,
>  static ssize_t csrow_dev_type_show(struct device *dev,
>  				   struct device_attribute *mattr, char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
> +
>  	struct csrow_info *csrow = to_csrow(dev);
>  
>  	return sysfs_emit(data, "%s\n", dev_types[csrow->channels[0]->dimm->dtype]);
> @@ -189,6 +199,8 @@ static ssize_t csrow_edac_mode_show(struct device *dev,
>  				    struct device_attribute *mattr,
>  				    char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
> +
>  	struct csrow_info *csrow = to_csrow(dev);
>  
>  	return sysfs_emit(data, "%s\n", edac_caps[csrow->channels[0]->dimm->edac_mode]);
> @@ -199,6 +211,7 @@ static ssize_t channel_dimm_label_show(struct device *dev,
>  				       struct device_attribute *mattr,
>  				       char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
>  	struct csrow_info *csrow = to_csrow(dev);
>  	unsigned int chan = to_channel(mattr);
>  	struct rank_info *rank = csrow->channels[chan];
> @@ -238,6 +251,7 @@ static ssize_t channel_dimm_label_store(struct device *dev,
>  static ssize_t channel_ce_count_show(struct device *dev,
>  				     struct device_attribute *mattr, char *data)
>  {
> +	pr_warn_once("Depcreated interface! Will be removed within two future releases. Please switch to using the new interface!\n");
>  	struct csrow_info *csrow = to_csrow(dev);
>  	unsigned int chan = to_channel(mattr);
>  	struct rank_info *rank = csrow->channels[chan];
> -- 

Depcreated -> Deprecated

And maybe the warning can go in an short inline function? Sorry, I
forgot if this came up already.

Also, "two future releases" is vague. And it may be confusing if this is
backported.

Does anyone have a better suggestion, or is this good as-is?

Thanks,
Yazen