[PATCH v3 1/3] drm/atomic-helper: Add atomic_disable CRTC helper callback

[Daniel Vetter]

On Fri, Aug 19, 2016 at 05:36:57PM +0800, Liu Ying wrote:
> Some display controllers need plane(s) to be disabled together with
> the relevant CRTC, e.g., the IPUv3 display controller for imx-drm.
> This patch adds atomic_disable CRTC helper callback so that
> old_crtc_state(as a parameter of the callback) could be used
> to get all appropriate active plane(s) of the old CRTC state for
> disable operation.
> 
> Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Philipp Zabel <p.zabel at pengutronix.de>
> Cc: David Airlie <airlied at linux.ie>
> Cc: Russell King <linux at armlinux.org.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Peter Senna Tschudin <peter.senna at gmail.com>
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Signed-off-by: Liu Ying <gnuiyl at gmail.com>
> ---
> v3:
> * Newly introduced in v3.
> 
>  drivers/gpu/drm/drm_atomic_helper.c      |  2 ++
>  include/drm/drm_modeset_helper_vtables.h | 14 ++++++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 9abe0a2..254bdde 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -749,6 +749,8 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
>  		/* Right function depends upon target state. */
>  		if (crtc->state->enable && funcs->prepare)
>  			funcs->prepare(crtc);
> +		else if (funcs->atomic_disable)
> +			 funcs->atomic_disable(crtc, old_crtc_state);
>  		else if (funcs->disable)
>  			funcs->disable(crtc);
>  		else
> diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
> index 686feec..16fd918 100644
> --- a/include/drm/drm_modeset_helper_vtables.h
> +++ b/include/drm/drm_modeset_helper_vtables.h
> @@ -391,6 +391,20 @@ struct drm_crtc_helper_funcs {
>  	 */
>  	void (*atomic_flush)(struct drm_crtc *crtc,
>  			     struct drm_crtc_state *old_crtc_state);
> +
> +	/**
> +	 * @atomic_disable:
> +	 *
> +	 * This callback should be used to disable the CRTC. It is called
> +	 * after all encoders connected to this CRTC have been shut off
> +	 * already using their own ->disable hook.
> +	 *
> +	 * This hook is used only by atomic helpers. Atomic drivers don't
> +	 * need to implement it if there's no need to disable anything at the
> +	 * CRTC level.

kernel-doc is a bit lacking compared to the one for @disable. And I think
on top of that it should explain better the difference with @disable (and
@disable should reference @atomic_disable too).
-Daniel

> +	 */
> +	void (*atomic_disable)(struct drm_crtc *crtc,
> +			       struct drm_crtc_state *old_crtc_state);
>  };
>  
>  /**
> -- 
> 2.7.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch