Re: [PATCH v3] drm/mediatek: check plane visibility in atomic_update

From: Matthias Brugger <matthias.bgg@gmail.com>
To: Hsin-Yi Wang <hsinyi@chromium.org>,
	linux-arm-kernel@lists.infradead.org,
	Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	dri-devel@lists.freedesktop.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
	yongqiang.niu@mediatek.com, tfiga@chromium.org
Subject: Re: [PATCH v3] drm/mediatek: check plane visibility in atomic_update
Date: Mon, 22 Jun 2020 17:44:14 +0200	[thread overview]
Message-ID: <e419427c-447a-8c82-3516-fc7f9b7ed661@gmail.com> (raw)
In-Reply-To: <20200622153106.112115-1-hsinyi@chromium.org>

On 22/06/2020 17:31, Hsin-Yi Wang wrote:
> Disable the plane if it's not visible. Otherwise mtk_ovl_layer_config()
> would proceed with invalid plane and we may see vblank timeout.
> 
> Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> Change-Id: Id5341d60ddfffc88a38d9db0caa089b2d6a1d29c

Seems like the Change-Id slipped in now.

Regards,
Matthias

> ---
> v3: Address comment
> v2: Add fixes tag
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_plane.c | 25 ++++++++++++++----------
>  1 file changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index c2bd683a87c8..92141a19681b 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -164,6 +164,16 @@ static int mtk_plane_atomic_check(struct drm_plane *plane,
>  						   true, true);
>  }
>  
> +static void mtk_plane_atomic_disable(struct drm_plane *plane,
> +				     struct drm_plane_state *old_state)
> +{
> +	struct mtk_plane_state *state = to_mtk_plane_state(plane->state);
> +
> +	state->pending.enable = false;
> +	wmb(); /* Make sure the above parameter is set before update */
> +	state->pending.dirty = true;
> +}
> +
>  static void mtk_plane_atomic_update(struct drm_plane *plane,
>  				    struct drm_plane_state *old_state)
>  {
> @@ -178,6 +188,11 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
>  	if (!crtc || WARN_ON(!fb))
>  		return;
>  
> +	if (!plane->state->visible) {
> +		mtk_plane_atomic_disable(plane, old_state);
> +		return;
> +	}
> +
>  	gem = fb->obj[0];
>  	mtk_gem = to_mtk_gem_obj(gem);
>  	addr = mtk_gem->dma_addr;
> @@ -200,16 +215,6 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
>  	state->pending.dirty = true;
>  }
>  
> -static void mtk_plane_atomic_disable(struct drm_plane *plane,
> -				     struct drm_plane_state *old_state)
> -{
> -	struct mtk_plane_state *state = to_mtk_plane_state(plane->state);
> -
> -	state->pending.enable = false;
> -	wmb(); /* Make sure the above parameter is set before update */
> -	state->pending.dirty = true;
> -}
> -
>  static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {
>  	.prepare_fb = drm_gem_fb_prepare_fb,
>  	.atomic_check = mtk_plane_atomic_check,
> 