Re: [PATCH] drm/stm: ltdc: improve pm_runtime to stop clocks

[Marek Vasut <marex@xxxxxxx>]

On 6/29/21 1:58 PM, Raphael GALLAIS-POU - foss wrote:

[...]

> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -425,10 +425,17 @@ static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
>   {
>   	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
>   	struct drm_device *ddev = crtc->dev;
> +	int ret;
>   
>   	DRM_DEBUG_DRIVER("\n");
>   
> -	pm_runtime_get_sync(ddev->dev);
> +	if (!pm_runtime_active(ddev->dev)) {
> +		ret = pm_runtime_get_sync(ddev->dev);

All these if (!pm_runtime_active()) then pm_runtime_get_sync() calls 
look like workaround for some larger issue. Shouldn't the pm_runtime do 
some refcounting on its own , so this shouldn't be needed ?