openwrt/target/linux/bcm27xx/patches-6.1/950-0404-drm-panel-panel-ilitek9881c-Add-prepare_upstream_fir.patch

From 942d55434af46aebe8f5508995807253a6b235b3 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Thu, 31 Mar 2022 12:05:04 +0100
Subject: [PATCH] drm/panel: panel-ilitek9881c: Add
 prepare_prev_first flag

The panel sends MIPI DCS commands during prepare and is expecting
the bus to remain in LP-11 state in-between.

Set the prepare_prev_first flag so that the upstream DSI host
is prepared / pre_enabled first, and therefore the bus is in a
defined state.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/panel/panel-ilitek-ili9881c.c | 1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
@@ -1131,6 +1131,7 @@ static int ili9881c_dsi_probe(struct mip
 	ctx->dsi = dsi;
 	ctx->desc = of_device_get_match_data(&dsi->dev);
 
+	ctx->panel.prepare_prev_first = true;
 	drm_panel_init(&ctx->panel, &dsi->dev, &ili9881c_funcs,
 		       DRM_MODE_CONNECTOR_DSI);