[PATCH 18/21] drm/mediatek: dsi: Improves the DSI lane setup robustness

[Chun-Kuang Hu]

Hi, Xinlei:

Could you help to review this patch?

Regards,
Chun-Kuang.

Alexandre Mergnat <amergnat at baylibre.com> 於 2023年3月9日 週四 下午10:23寫道：
>
> Currently, mtk_dsi_lane_ready (which setup the DSI lane) is triggered
> before mtk_dsi_poweron. lanes_ready flag toggle to true during
> mtk_dsi_lane_ready function, and the DSI module is set up during
> mtk_dsi_poweron.
>
> Later, during panel driver init, mtk_dsi_lane_ready is triggered but does
> nothing because lanes are considered ready. Unfortunately, when the panel
> driver try to communicate, the DSI returns a timeout.
>
> The solution found here is to put lanes_ready flag to false after the DSI
> module setup into mtk_dsi_poweron to init the DSI lanes after the power /
> setup of the DSI module.
>
> Signed-off-by: Alexandre Mergnat <amergnat at baylibre.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 3b7d13028fb6..35c36cc05c04 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -667,6 +667,8 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
>         mtk_dsi_config_vdo_timing(dsi);
>         mtk_dsi_set_interrupt_enable(dsi);
>
> +       dsi->lanes_ready = false;
> +
>         return 0;
>  err_disable_engine_clk:
>         clk_disable_unprepare(dsi->engine_clk);
>
> --
> b4 0.10.1