Re: [PATCH v3 2/4] drm/mxsfb: Add pm_runtime calls to pipe_enable/disable

[Stefan Agner <stefan@agner.ch>]

On 06.08.2018 21:31, Leonard Crestez wrote:
> Adding lcdif nodes to a power domain currently results in
> black/corrupted screens or hangs because power is not correctly enabled
> when required.
> 
> Ensure power is on when display is active by adding
> pm_runtime_get/put_sync to mxsfb_pipe_enable/disable.
> 
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>

Reviewed-by: Stefan Agner <stefan@agner.ch>

> ---
>  drivers/gpu/drm/mxsfb/mxsfb_drv.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> index ffe5137ccaf8..68d79f5dc0d3 100644
> --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> @@ -101,23 +101,27 @@ static const struct drm_mode_config_funcs
> mxsfb_mode_config_funcs = {
>  static void mxsfb_pipe_enable(struct drm_simple_display_pipe *pipe,
>  			      struct drm_crtc_state *crtc_state,
>  			      struct drm_plane_state *plane_state)
>  {
>  	struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe);
> +	struct drm_device *drm = pipe->plane.dev;
>  
> +	pm_runtime_get_sync(drm->dev);
>  	drm_panel_prepare(mxsfb->panel);
>  	mxsfb_crtc_enable(mxsfb);
>  	drm_panel_enable(mxsfb->panel);
>  }
>  
>  static void mxsfb_pipe_disable(struct drm_simple_display_pipe *pipe)
>  {
>  	struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe);
> +	struct drm_device *drm = pipe->plane.dev;
>  
>  	drm_panel_disable(mxsfb->panel);
>  	mxsfb_crtc_disable(mxsfb);
>  	drm_panel_unprepare(mxsfb->panel);
> +	pm_runtime_put_sync(drm->dev);
>  }
>  
>  static void mxsfb_pipe_update(struct drm_simple_display_pipe *pipe,
>  			      struct drm_plane_state *plane_state)
>  {