Re: [PATCH v7 08/10] drm: bridge: samsung-dsim: Add input_bus_flags

Marek Vasut
2022-10-15T21:38:20Z

On 10/5/22 17:13, Jagan Teki wrote:

[...]

> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index f714e49c1eab..f5cd80641cea 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -1601,6 +1601,10 @@ static const struct samsung_dsim_host_ops samsung_dsim_generic_host_ops = {
> .unregister_host = samsung_dsim_unregister_host,
> };
>
> +static const struct drm_bridge_timings samsung_dsim_bridge_timings = {
> + .input_bus_flags = DRM_BUS_FLAG_DE_LOW,
> +};
> +
> int samsung_dsim_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -1681,6 +1685,7 @@ int samsung_dsim_probe(struct platform_device *pdev)
>
> dsi->bridge.funcs = &samsung_dsim_bridge_funcs;
> dsi->bridge.of_node = dev->of_node;
> + dsi->bridge.timings = &samsung_dsim_bridge_timings;

Is this really valid on Exynos too ?

My impression is that the DE_LOW requirement is only needed for MX8MM/MN
where the LCDIF-DSIM glue logic inverts the HS/VS/DE signals, while on
all other platforms (at least MX8MP) the inversion does not take place,
so DE is really active HIGH there.