Re: [PATCH v6 1/1] drm/mediatek: force hsa hbp hfp packets multiple of lanenum to avoid screen shift

From: Chun-Kuang Hu
Date: Mon Aug 09 2021 - 10:45:09 EST


Hi, Jitao:

Jitao Shi <jitao.shi@xxxxxxxxxxxx> 於 2021年8月8日 週日 下午9:41寫道:
>
> The bridge chip ANX7625 requires the packets on lanes aligned at the end,
> or ANX7625 will shift the screen.

In anx7625_attach_dsi(), it call mipi_dsi_attach(), and it call into
mtk_dsi_host_attach().
I would like to pass this information from anx7623 driver to mtk_dsi
driver when attach.

Regards,
Chun-Kuang.

>
> Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
> ---
> 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..033234d51e86 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_device_is_compatible(dsi->next_bridge->of_node,
> + "analogix,anx7625");
> +
> drm_bridge_add(&dsi->bridge);
>
> ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
> --
> 2.25.1