[RFC 5/6] drm/xe/pm: D3Cold target state

[Ville Syrjälä]

On Mon, Feb 24, 2025 at 10:18:48PM +0530, Anshuman Gupta wrote:
> Trade-off D3Cold target state based upon current vram usages.
> if vram usages is greater then vram_d3cold_threshold and GPU
> has display connected 

Why would anyone care about displays being connected or not?

> then target D3Cold state is D3Cold-VRSR
> otherwise target state is D3COLD-Off.
> 
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  drivers/gpu/drm/xe/display/xe_display.c | 22 ++++++++++++++++++++++
>  drivers/gpu/drm/xe/display/xe_display.h |  1 +
>  drivers/gpu/drm/xe/xe_pm.c              | 12 ++++++++++++
>  3 files changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/display/xe_display.c b/drivers/gpu/drm/xe/display/xe_display.c
> index 02a413a07382..140a43d6b1b6 100644
> --- a/drivers/gpu/drm/xe/display/xe_display.c
> +++ b/drivers/gpu/drm/xe/display/xe_display.c
> @@ -548,3 +548,25 @@ int xe_display_probe(struct xe_device *xe)
>  	unset_display_features(xe);
>  	return 0;
>  }
> +
> +bool xe_display_connected(struct xe_device *xe)
> +{
> +	struct drm_connector *list_connector;
> +	struct drm_connector_list_iter iter;
> +	bool ret = false;
> +
> +	mutex_lock(&xe->drm.mode_config.mutex);
> +	drm_connector_list_iter_begin(&xe->drm, &iter);
> +
> +	drm_for_each_connector_iter(list_connector, &iter) {
> +		if (list_connector->status == connector_status_connected) {
> +			ret = true;
> +			break;
> +		}
> +	}
> +
> +	drm_connector_list_iter_end(&iter);
> +	mutex_unlock(&xe->drm.mode_config.mutex);
> +
> +	return ret;
> +}
> diff --git a/drivers/gpu/drm/xe/display/xe_display.h b/drivers/gpu/drm/xe/display/xe_display.h
> index 685dc74402fb..c6bc54323084 100644
> --- a/drivers/gpu/drm/xe/display/xe_display.h
> +++ b/drivers/gpu/drm/xe/display/xe_display.h
> @@ -40,6 +40,7 @@ void xe_display_pm_resume(struct xe_device *xe);
>  void xe_display_pm_runtime_suspend(struct xe_device *xe);
>  void xe_display_pm_runtime_suspend_late(struct xe_device *xe);
>  void xe_display_pm_runtime_resume(struct xe_device *xe);
> +bool xe_display_connected(struct xe_device *xe);
>  
>  #else
>  
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index 81e67b5693dc..6d28aedcb062 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -198,6 +198,14 @@ static void xe_rpm_lockmap_release(const struct xe_device *xe)
>  			 &xe_pm_runtime_d3cold_map);
>  }
>  
> +static void xe_pm_suspend_prepare(struct xe_device *xe)
> +{
> +	if (pm_suspend_target_state == PM_SUSPEND_TO_IDLE)
> +		xe_pm_d3cold_allowed_toggle(xe);
> +	else
> +		xe->d3cold.allowed = XE_D3COLD_OFF;
> +}
> +
>  /**
>   * xe_pm_suspend - Helper for System suspend, i.e. S0->S3 / S0->S2idle
>   * @xe: xe device instance
> @@ -213,6 +221,8 @@ int xe_pm_suspend(struct xe_device *xe)
>  	drm_dbg(&xe->drm, "Suspending device\n");
>  	trace_xe_pm_suspend(xe, __builtin_return_address(0));
>  
> +	xe_pm_suspend_prepare(xe);
> +
>  	err = xe_pxp_pm_suspend(xe->pxp);
>  	if (err)
>  		goto err;
> @@ -875,6 +885,8 @@ void xe_pm_d3cold_allowed_toggle(struct xe_device *xe)
>  
>  	if (total_vram_used_mb < xe->d3cold.vram_threshold)
>  		xe->d3cold.allowed = XE_D3COLD_OFF;
> +	else if (xe->d3cold.vrsr_capable && xe_display_connected(xe))
> +		xe->d3cold.allowed = XE_D3COLD_VRSR;
>  	else
>  		xe->d3cold.allowed = XE_D3HOT;
>  
> -- 
> 2.34.1

-- 
Ville Syrjälä
Intel