[PATCH v5 2/2] drm/mediatek: force hsa hbp hfp packets multiple of lanenum to avoid screen shift

[Jitao Shi]

The bridge chip ANX7625 requires the packets on lanes aligned at the end,
or ANX7625 will shift the screen.

Signed-off-by: Jitao Shi <jitao....@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c 
b/drivers/gpu/drm/mediatek/mtk_dsi.c
index ae403c67cbd9..4735e0092ffe 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -194,6 +194,8 @@ struct mtk_dsi {
        struct clk *hs_clk;
 
        u32 data_rate;
+       /* force dsi line end without dsi_null data */
+       bool force_dsi_end_without_null;
 
        unsigned long mode_flags;
        enum mipi_dsi_pixel_format format;
@@ -499,6 +501,13 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
                DRM_WARN("HFP + HBP less than d-phy, FPS will under 60Hz\n");
        }
 
+       if (dsi->force_dsi_end_without_null) {
+               horizontal_sync_active_byte = 
roundup(horizontal_sync_active_byte, dsi->lanes) - 2;
+               horizontal_frontporch_byte = 
roundup(horizontal_frontporch_byte, dsi->lanes) - 2;
+               horizontal_backporch_byte = roundup(horizontal_backporch_byte, 
dsi->lanes) - 2;
+               horizontal_backporch_byte -= (vm->hactive * dsi_tmp_buf_bpp + 
2) % dsi->lanes;
+       }
+
        writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC);
        writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC);
        writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);
@@ -1095,6 +1104,10 @@ static int mtk_dsi_probe(struct platform_device *pdev)
        dsi->bridge.of_node = dev->of_node;
        dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
 
+       if (dsi->next_bridge)
+               dsi->force_dsi_end_without_null = 
of_property_read_bool(dsi->next_bridge->of_node,
+                                                                       
"force_dsi_end_without_null");
+
        drm_bridge_add(&dsi->bridge);
 
        ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
-- 
2.25.1