[PATCH] drm/xe/guc: Make creation of SLPC debugfs files conditional

[Upadhyay, Tejas]

> -----Original Message-----
> From: Bhatia, Aradhya <aradhya.bhatia at intel.com>
> Sent: 15 May 2025 15:19
> To: Roper, Matthew D <matthew.d.roper at intel.com>
> Cc: Intel XE List <intel-xe at lists.freedesktop.org>; Upadhyay, Tejas
> <tejas.upadhyay at intel.com>; Ghimiray, Himal Prasad
> <himal.prasad.ghimiray at intel.com>; Bhatia, Aradhya
> <aradhya.bhatia at intel.com>
> Subject: [PATCH] drm/xe/guc: Make creation of SLPC debugfs files conditional
> 
> Platforms that do not support SLPC are exempted from the GuC PC support.
> The GuC PC does not get initialized, and neither do its BOs get created.
> 
> This causes a problem because the GuC PC debugfs file is still being created.
> Whenever the file is attempted to read, it causes a NULL pointer dereference
> on the supposed BO of the GuC PC.
> 
> So, make the creation of SLPC debugfs files conditional to when SLPC features
> are supported.
> 
> Suggested-by: Matt Roper <matthew.d.roper at intel.com>
> Signed-off-by: Aradhya Bhatia <aradhya.bhatia at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_debugfs.c | 17 ++++++++++++++---
>  1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_debugfs.c
> b/drivers/gpu/drm/xe/xe_guc_debugfs.c
> index f33013f8a0f3..0b102ab46c4d 100644
> --- a/drivers/gpu/drm/xe/xe_guc_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_guc_debugfs.c
> @@ -113,23 +113,34 @@ static const struct drm_info_list
> vf_safe_debugfs_list[] = {
>  	{ "guc_ctb", .show = guc_debugfs_show, .data = guc_ctb },  };
> 
> +/* For GuC debugfs files that require the SLPC support */ static const
> +struct drm_info_list slpc_debugfs_list[] = {
> +	{ "guc_pc", .show = guc_debugfs_show, .data = guc_pc }, };
> +
>  /* everything else should be added here */  static const struct drm_info_list
> pf_only_debugfs_list[] = {
>  	{ "guc_log", .show = guc_debugfs_show, .data = guc_log },
>  	{ "guc_log_dmesg", .show = guc_debugfs_show, .data =
> guc_log_dmesg },
> -	{ "guc_pc", .show = guc_debugfs_show, .data = guc_pc },

You need fixes tag here it seems. With that,
Reviewed-by: Tejas Upadhyay <tejas.upadhyay at intel.com>

Tejas
>  };
> 
>  void xe_guc_debugfs_register(struct xe_guc *guc, struct dentry *parent)  {
> -	struct drm_minor *minor = guc_to_xe(guc)->drm.primary;
> +	struct xe_device *xe =  guc_to_xe(guc);
> +	struct drm_minor *minor = xe->drm.primary;
> 
>  	drm_debugfs_create_files(vf_safe_debugfs_list,
>  				 ARRAY_SIZE(vf_safe_debugfs_list),
>  				 parent, minor);
> 
> -	if (!IS_SRIOV_VF(guc_to_xe(guc)))
> +	if (!IS_SRIOV_VF(xe)) {
>  		drm_debugfs_create_files(pf_only_debugfs_list,
>  					 ARRAY_SIZE(pf_only_debugfs_list),
>  					 parent, minor);
> +
> +		if (!xe->info.skip_guc_pc)
> +			drm_debugfs_create_files(slpc_debugfs_list,
> +
> ARRAY_SIZE(slpc_debugfs_list),
> +						 parent, minor);
> +	}
>  }
> 
> base-commit: 3d6670fab64cb00b5e6ed80d2517147db533faf1
> --
> 2.43.0