drm/xe: xe_hw_engine_class: Add fault injection and improve error handling in kobj_xe_hw_engine_class

[Upadhyay, Tejas]

> -----Original Message-----
> From: Thomas, Sobin <sobin.thomas at intel.com>
> Sent: 05 April 2025 12:47
> To: intel-xe at lists.freedesktop.org
> Cc: Upadhyay, Tejas <tejas.upadhyay at intel.com>
> Subject: drm/xe: xe_hw_engine_class: Add fault injection and improve error
> handling in kobj_xe_hw_engine_class
> 
> - Added fault injection for `kobj_xe_hw_engine_class` to enhance coverage.
> - Improved error handling by checking for `IS_ERR_OR_NULL` on `keclass` and
>   propagating the error using `PTR_ERR`.
> 
> Can be tested using inject-fault-probe-function-kobj_xe_hw_engine_class
> 
> Signed-off-by: Sobin Thomas <sobin.thomas at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
> b/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
> index 640950172088..0cafe1175389 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
> +++ b/drivers/gpu/drm/xe/xe_hw_engine_class_sysfs.c
> @@ -571,6 +571,7 @@ kobj_xe_hw_engine_class(struct xe_device *xe, struct
> kobject *parent, const char
> 
>  	return keclass;
>  }
> +ALLOW_ERROR_INJECTION(kobj_xe_hw_engine_class, NULL);
> 
>  static void hw_engine_class_defaults_fini(void *arg)  { @@ -662,8 +663,8
> @@ int xe_hw_engine_class_sysfs_init(struct xe_gt *gt)
>  		}
> 
>  		keclass = kobj_xe_hw_engine_class(xe, kobj, name);
> -		if (!keclass) {
> -			err = -EINVAL;
> +		if (IS_ERR_OR_NULL(keclass)) {
> +			err = PTR_ERR(keclass);

LGTM,
Reviewed-by: Tejas Upadhyay <tejas.upadhyay at intel.com>

>  			goto err_object;
>  		}
> 
> --
> 2.34.1