Re: [PATCH 6/6] drm/msm/mdp5: Don't use async plane update path if plane visibility changes

[Gustavo Padovan <gustavo@padovan.org>]

Hi Archit,

2017-10-27 Archit Taneja <architt@codeaurora.org>:

> When a plane moves out of bounds (i.e, outside the crtc clip region), the
> plane state's "visible" parameter changes to false. When this happens, we
> (a) release the hwpipe resources away from it, and
> (b) unstage the corresponding hwpipe(s) from the Layer Mixers in the CRTC.
> 
> (a) requires use to acquire the global atomic state and assign a new
> hwpipe. (b) requires us to re-configure the Layer Mixer, which is done in
> the CRTC. We don't want to do these things in the async plane update path,
> so return an error if the new state's "visible" isn't the same as the
> current state's "visible".
> 
> Cc: Gustavo Padovan <gustavo.padovan@collabora.com>
> Signed-off-by: Archit Taneja <architt@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> index f1cf367e853d..be50445f9901 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> @@ -470,6 +470,9 @@ static int mdp5_plane_atomic_async_check(struct drm_plane *plane,
>  {
>  	struct mdp5_plane_state *mdp5_state = to_mdp5_plane_state(state);
>  	struct drm_crtc_state *crtc_state;
> +	struct drm_rect clip;
> +	int min_scale, max_scale;
> +	int ret;
>  
>  	crtc_state = drm_atomic_get_existing_crtc_state(state->state,
>  							state->crtc);
> @@ -495,6 +498,28 @@ static int mdp5_plane_atomic_async_check(struct drm_plane *plane,
>  	    plane->state->fb != state->fb)
>  		return -EINVAL;
>  
> +	clip.x1 = 0;
> +	clip.y1 = 0;
> +	clip.x2 = crtc_state->adjusted_mode.hdisplay;
> +	clip.y2 = crtc_state->adjusted_mode.vdisplay;
> +	min_scale = FRAC_16_16(1, 8);
> +	max_scale = FRAC_16_16(8, 1);
> +
> +	ret = drm_plane_helper_check_state(state, &clip, min_scale,
> +					   max_scale, true, true);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * if the visibility of the plane changes (i.e, if the cursor is
> +	 * clipped out completely, we can't take the async path because
> +	 * we need to stage/unstage the plane from the Layer Mixer(s). We
> +	 * also assign/unassign the hwpipe(s) tied to the plane. We avoid
> +	 * taking the fast path for both these reasons.
> +	 */
> +	if (state->visible != plane->state->visible)
> +		return -EINVAL;
> +
>  	return 0;
>  }

Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>

Gustavo