drm/rockchip: vop: fix NV12 video display error

fixup the scale calculation formula on the case
src_height == (dst_height/2).

Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Reviewed-by: Sandy huang <sandy.huang@rock-chips.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1501494586-6984-1-git-send-email-mark.yao@rock-chips.com

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
index 9979fd0c2282..27eefbfcf3d0 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
@@ -282,6 +282,9 @@ static inline uint16_t scl_get_bili_dn_vskip(int src_h, int dst_h,
 
         act_height = (src_h + vskiplines - 1) / vskiplines;
 
+        if (act_height == dst_h)
+                return GET_SCL_FT_BILI_DN(src_h, dst_h) / vskiplines;
+
         return GET_SCL_FT_BILI_DN(act_height, dst_h);
 }