Re: [PATCH v2 1/2] dt-bindings: display: bridge: ti, sn65dsi83: Add dual-link video mode property

[Luca Ceresoli]

Hello Sudarshan,

On Thu Mar 12, 2026 at 5:37 AM CET, Sudarshan Shetty wrote:
> Add a new optional device tree property `ti,dual-link-video-mode`
> to indicate that the bridge should configure the device for
> dual-link LVDS video mode.
>
> In dual-link configurations, some panels require the horizontal
> timing parameters to be adjusted before programming them into
> the device. In such cases, the horizontal timing values must be
> divided by two when operating in dual-link mode.
>
> Signed-off-by: Sudarshan Shetty <tessolveupstream@xxxxxxxxx>

This is not needed. Dual link mode is already implied by the presence of
port@2 and port@3.

Also, the driver implements that already, and handles even/odd pixel swap
as well:

	ctx->lvds_dual_link = false;
	ctx->lvds_dual_link_even_odd_swap = false;
	if (model != MODEL_SN65DSI83) {
		struct device_node *port2, *port3;
		int dual_link;

		port2 = of_graph_get_port_by_id(dev->of_node, 2);
		port3 = of_graph_get_port_by_id(dev->of_node, 3);
		dual_link = drm_of_lvds_get_dual_link_pixel_order(port2, port3);
		of_node_put(port2);
		of_node_put(port3);

		if (dual_link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS) {
			ctx->lvds_dual_link = true;
			/* Odd pixels to LVDS Channel A, even pixels to B */
			ctx->lvds_dual_link_even_odd_swap = false;
		} else if (dual_link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {
			ctx->lvds_dual_link = true;
			/* Even pixels to LVDS Channel A, odd pixels to B */
			ctx->lvds_dual_link_even_odd_swap = true;
		}
	}

(https://elixir.bootlin.com/linux/v7.0-rc3/source/drivers/gpu/drm/bridge/ti-sn65dsi83.c#L895-L916)

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com