[PATCH v2] drm/mediatek: dsi: fix scrolling of panel with small hfp or hbp

[Jitao Shi]

horizontal_backporch_byte should be hbp * bpp - hbp extra bytes.
So remove the wrong subtraction 10.

Signed-off-by: Jitao Shi <jitao....@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c 
b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 270bf22c98fe..5d031e634571 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -473,14 +473,13 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
        horizontal_sync_active_byte = (vm->hsync_len * dsi_tmp_buf_bpp - 10);
 
        if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
-               horizontal_backporch_byte =
-                       (vm->hback_porch * dsi_tmp_buf_bpp - 10);
+               horizontal_backporch_byte = vm->hback_porch * dsi_tmp_buf_bpp;
        else
-               horizontal_backporch_byte = ((vm->hback_porch + vm->hsync_len) *
-                       dsi_tmp_buf_bpp - 10);
+               horizontal_backporch_byte = (vm->hback_porch + vm->hsync_len) *
+                                           dsi_tmp_buf_bpp;
 
        data_phy_cycles = timing->lpx + timing->da_hs_prepare +
-                         timing->da_hs_zero + timing->da_hs_exit + 3;
+                         timing->da_hs_zero + timing->da_hs_exit;
 
        if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
                if ((vm->hfront_porch + vm->hback_porch) * dsi_tmp_buf_bpp >
-- 
2.12.5