Re: [PATCH v4 1/2] drm/xe: Use IBC v3 on PTL

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Jul 15, 2026 at 04:58:23PM -0700, Vinay Belgaumkar wrote:
> Intelligent Bias Control (IBC) v3 algorithm in GuC has PTL specific
> optimizations. This version selection param is only available GuC 70.48.0
> onwards.
> 
> v4: Fix sashiko.dev review issue
> 
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> ---
>  drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h | 1 +
>  drivers/gpu/drm/xe/xe_guc_pc.c                | 9 +++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h b/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h
> index ce5c59517528..57baa68bcba4 100644
> --- a/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h
> +++ b/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h
> @@ -119,6 +119,7 @@ enum slpc_param_id {
>  	SLPC_PARAM_STRATEGIES = 26,
>  	SLPC_PARAM_POWER_PROFILE = 27,
>  	SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY = 28,
> +	SLPC_PARAM_SET_IBC_VERSION = 29,
>  	SLPC_MAX_PARAM = 32,
>  };
>  
> diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
> index 59f2fa79ad42..550da596fdd9 100644
> --- a/drivers/gpu/drm/xe/xe_guc_pc.c
> +++ b/drivers/gpu/drm/xe/xe_guc_pc.c
> @@ -1236,6 +1236,15 @@ static int pc_modify_defaults(struct xe_guc_pc *pc)
>  		ret = pc_action_set_dcc(pc, false);
>  		if (unlikely(ret))
>  			xe_gt_err(gt, "Failed to modify DCC default: %pe\n", ERR_PTR(ret));
> +
> +		if (!ret && xe_gt_is_main_type(gt) &&

I don't like the cascade of ret handling.
We should perhaps do

if (unlikely(ret)) {
 print msg;
return ret; or a goto out;
}

> +		    GUC_FIRMWARE_VER_AT_LEAST(&gt->uc.guc, 70, 48, 0)) {
> +			ret = pc_action_set_param(pc,
> +						  SLPC_PARAM_SET_IBC_VERSION,
> +						  3);
> +			if (unlikely(ret))
> +				xe_gt_err(gt, "Failed to modify IBC version: %pe\n", ERR_PTR(ret));
> +		}
>  	}
>  

out:

>  	return ret;
> -- 
> 2.38.1
>