[PATCH] drm/mediatek: Fix can't get component for external display plane.

[CK Hu]

Hi, Pi-Hsun:


On Wed, 2019-11-27 at 18:04 +0800, Pi-Hsun Shih wrote:
> From: Yongqiang Niu <yongqiang.niu at mediatek.com>
> 
> The original logic is ok for primary display, but will not find out
> component for external display.
> 
> For example, plane->index is 6 for external display, but there are only
> 2 layer nr in external display, and this condition will never happen:
> if (plane->index < (count + mtk_ddp_comp_layer_nr(comp)))
> 
> Fix this by using the offset of the plane to mtk_crtc->planes as index,
> instead of plane->index.

Reviewed-by: CK Hu <ck.hu at mediatek.com>

Regards,
CK

> 
> Fixes: d6b53f68356f ("drm/mediatek: Add helper to get component for a plane")
> Signed-off-by: Yongqiang Niu <yongqiang.niu at mediatek.com>
> Signed-off-by: Pi-Hsun Shih <pihsun at chromium.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index f80a8ba75977..b34e7d70702a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -215,11 +215,12 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
>  	struct mtk_ddp_comp *comp;
>  	int i, count = 0;
> +	unsigned int local_index = plane - mtk_crtc->planes;
>  
>  	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
>  		comp = mtk_crtc->ddp_comp[i];
> -		if (plane->index < (count + mtk_ddp_comp_layer_nr(comp))) {
> -			*local_layer = plane->index - count;
> +		if (local_index < (count + mtk_ddp_comp_layer_nr(comp))) {
> +			*local_layer = local_index - count;
>  			return comp;
>  		}
>  		count += mtk_ddp_comp_layer_nr(comp);
> 
> base-commit: 1875ff320f14afe21731a6e4c7b46dd33e45dfaa