Re: [PATCH v4 1/2] drm/xe/guc: Split xe_guc_ct_enable()

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

On Thu, Sep 04, 2025 at 02:44:38PM +0530, Raag Jadav wrote:
> In preparation of usecases which require dynamically enabling GuC CT state,
> split xe_guc_ct_enable().
> 
> Suggested-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc.c    |  2 +-
>  drivers/gpu/drm/xe/xe_guc_ct.c | 34 ++++++++++++++++++++++++++--------
>  drivers/gpu/drm/xe/xe_guc_ct.h |  3 ++-
>  3 files changed, 29 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index b3a6408a5760..fd82eef8f372 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -1355,7 +1355,7 @@ int xe_guc_enable_communication(struct xe_guc *guc)
>  		guc_enable_irq(guc);
>  	}
>  
> -	err = xe_guc_ct_enable(&guc->ct);
> +	err = xe_guc_ct_register(&guc->ct);
>  	if (err)
>  		return err;
>  
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> index e431ff73227c..f2b2db780e53 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> @@ -504,7 +504,31 @@ static void ct_exit_safe_mode(struct xe_guc_ct *ct)
>  		xe_gt_dbg(ct_to_gt(ct), "GuC CT safe-mode disabled\n");
>  }
>  
> -int xe_guc_ct_enable(struct xe_guc_ct *ct)
> +/**
> + * xe_guc_ct_enable() - Enable GuC CT
> + * @ct: the &xe_guc_ct
> + *
> + * Set GuC CT to enabled state and ready to send/received new messages.
> + */
> +void xe_guc_ct_enable(struct xe_guc_ct *ct)
> +{
> +	guc_ct_change_state(ct, XE_GUC_CT_STATE_ENABLED);
> +
> +	smp_mb();
> +	wake_up_all(&ct->wq);
> +
> +	ct_enter_safe_mode(ct);

Where is the  if (ct_needs_safe_mode(ct)) ?
This change is not mentioned in the commit message and might have
implications specially on initialization and SRIOV flows?!

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>


> +}
> +
> +/**
> + * xe_guc_ct_register() - Register GuC CT
> + * @ct: the &xe_guc_ct
> + *
> + * Initialize and register H2G and G2H CTBs and enable GuC CT.
> + *
> + * Return: 0 on success, negative error code otherwise.
> + */
> +int xe_guc_ct_register(struct xe_guc_ct *ct)
>  {
>  	struct xe_device *xe = ct_to_xe(ct);
>  	struct xe_gt *gt = ct_to_gt(ct);
> @@ -528,13 +552,7 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct)
>  	if (err)
>  		goto err_out;
>  
> -	guc_ct_change_state(ct, XE_GUC_CT_STATE_ENABLED);
> -
> -	smp_mb();
> -	wake_up_all(&ct->wq);
> -
> -	if (ct_needs_safe_mode(ct))
> -		ct_enter_safe_mode(ct);
> +	xe_guc_ct_enable(ct);
>  
>  #if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
>  	/*
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
> index cf41210ab30a..c821517e87d0 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.h
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.h
> @@ -14,8 +14,9 @@ struct xe_device;
>  int xe_guc_ct_init_noalloc(struct xe_guc_ct *ct);
>  int xe_guc_ct_init(struct xe_guc_ct *ct);
>  int xe_guc_ct_init_post_hwconfig(struct xe_guc_ct *ct);
> -int xe_guc_ct_enable(struct xe_guc_ct *ct);
> +void xe_guc_ct_enable(struct xe_guc_ct *ct);
>  void xe_guc_ct_disable(struct xe_guc_ct *ct);
> +int xe_guc_ct_register(struct xe_guc_ct *ct);
>  void xe_guc_ct_stop(struct xe_guc_ct *ct);
>  void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
>  
> -- 
> 2.34.1
>