Re: [PATCH v2 2/2] drm/xe/sysfs: Simplify sysfs registration

[Raag Jadav <raag.jadav@intel.com>]

On Tue, Sep 16, 2025 at 07:00:29PM +0200, Michal Wajdeczko wrote:
> Instead of manually maintaining each sysfs file define and use
> attribute groups and register them using device managed function.
> Then use is_visible() to filter-out unsupported attributes.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Raag Jadav <raag.jadav@intel.com>
> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
> v2: rebased, reordered
> ---
>  drivers/gpu/drm/xe/xe_device_sysfs.c | 104 +++++++++++----------------
>  1 file changed, 41 insertions(+), 63 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device_sysfs.c b/drivers/gpu/drm/xe/xe_device_sysfs.c
> index 896484c8fbcc..c5151c86a98a 100644
> --- a/drivers/gpu/drm/xe/xe_device_sysfs.c
> +++ b/drivers/gpu/drm/xe/xe_device_sysfs.c
> @@ -71,6 +71,15 @@ vram_d3cold_threshold_store(struct device *dev, struct device_attribute *attr,
>  
>  static DEVICE_ATTR_RW(vram_d3cold_threshold);
>  
> +static struct attribute *vram_attrs[] = {
> +	&dev_attr_vram_d3cold_threshold.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group vram_attr_group = {
> +	.attrs = vram_attrs,
> +};
> +
>  static ssize_t
>  lb_fan_control_version_show(struct device *dev, struct device_attribute *attr, char *buf)
>  {
> @@ -149,8 +158,16 @@ lb_voltage_regulator_version_show(struct device *dev, struct device_attribute *a
>  }
>  static DEVICE_ATTR_ADMIN_RO(lb_voltage_regulator_version);
>  
> -static int late_bind_create_files(struct device *dev)
> +static struct attribute *late_bind_attrs[] = {
> +	&dev_attr_lb_fan_control_version.attr,
> +	&dev_attr_lb_voltage_regulator_version.attr,
> +	NULL
> +};
> +
> +static umode_t late_bind_attr_is_visible(struct kobject *kobj,
> +					 struct attribute *attr, int n)
>  {
> +	struct device *dev = kobj_to_dev(kobj);
>  	struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
>  	struct xe_tile *root = xe_device_get_root_tile(xe);
>  	u32 cap = 0;
> @@ -160,51 +177,25 @@ static int late_bind_create_files(struct device *dev)
>  
>  	ret = xe_pcode_read(root, PCODE_MBOX(PCODE_LATE_BINDING, GET_CAPABILITY_STATUS, 0),
>  			    &cap, NULL);
> -	if (ret) {
> -		if (ret == -ENXIO) {
> -			drm_dbg(&xe->drm, "Late binding not supported by firmware\n");
> -			ret = 0;
> -		}
> -		goto out;
> -	}
> -
> -	if (REG_FIELD_GET(V1_FAN_SUPPORTED, cap)) {
> -		ret = sysfs_create_file(&dev->kobj, &dev_attr_lb_fan_control_version.attr);
> -		if (ret)
> -			goto out;
> -	}
> -
> -	if (REG_FIELD_GET(VR_PARAMS_SUPPORTED, cap))
> -		ret = sysfs_create_file(&dev->kobj, &dev_attr_lb_voltage_regulator_version.attr);
> -out:

>  	xe_pm_runtime_put(xe);

The device is already in D0 while probing so runtime PM is probably
not needed here.

Raag