[PATCH v3 1/2] drm/mediatek: force hsa hbp hfp packets multiple of lanenum to avoid screen shift

[PATCH v3 1/2] 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.shi@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
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[PATCH v3 2/2] dt-bindings: mediatek: add force_dsi_end_without_null for dsi

[Jitao Shi]

Some bridge chip will shift screen when the dsi data does't ent at
the same time in line.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 .../devicetree/bindings/display/mediatek/mediatek,dsi.txt     | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
index 8238a86686be..1c2f53f3ac3d 100644
--- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
+++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
@@ -19,6 +19,10 @@ Required properties:
   Documentation/devicetree/bindings/graph.txt. This port should be connected
   to the input port of an attached DSI panel or DSI-to-eDP encoder chip.
 
+Optional properties:
+- force_dsi_end_without_null: Some bridge chip(ex. ANX7625) requires the
+  packets on lanes aligned at the end.
+
 MIPI TX Configuration Module
 ============================
 
-- 
2.25.1
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Re: [PATCH v3 2/2] dt-bindings: mediatek: add force_dsi_end_without_null for dsi

[CK Hu]

Hi, Jitao:

On Mon, 2021-07-26 at 10:11 +0800, Jitao Shi wrote:
> Some bridge chip will shift screen when the dsi data does't ent at
> the same time in line.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  .../devicetree/bindings/display/mediatek/mediatek,dsi.txt     | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
> index 8238a86686be..1c2f53f3ac3d 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
> @@ -19,6 +19,10 @@ Required properties:
>    Documentation/devicetree/bindings/graph.txt. This port should be connected
>    to the input port of an attached DSI panel or DSI-to-eDP encoder chip.
>  
> +Optional properties:
> +- force_dsi_end_without_null: Some bridge chip(ex. ANX7625) requires the
> +  packets on lanes aligned at the end.
> +

I think you should add this property in [1] because this limitation is
ANX7625's limitation.

[1]
Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml

Regards,
CK

>  MIPI TX Configuration Module
>  ============================
>  

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