From 605c83753d97946aab176735020a33ebfb0b4615 Mon Sep 17 00:00:00 2001
From: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Date: Thu, 30 Sep 2021 10:31:50 +0200
Subject: [PATCH] drm/mediatek: mtk_dsi: Reset the dsi0 hardware
Git-commit: 605c83753d97946aab176735020a33ebfb0b4615
Patch-mainline: v5.16-rc1
References: git-fixes

Reset dsi0 HW to default when power on. This prevents to have different
settingis between the bootloader and the kernel.

As not all Mediatek boards have the reset consumer configured in their
board description, also is not needed on all of them, the reset is optional,
so the change is compatible with all boards.

Cc: Jitao Shi <jitao.shi@mediatek.com>
Suggested-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20210930103105.v4.7.Idbb4727ddf00ba2fe796b630906baff10d994d89@changeid
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 93b40c245f00..5d90d2eb0019 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -11,6 +11,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 
 #include <video/mipi_display.h>
 #include <video/videomode.h>
@@ -980,8 +981,10 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct mtk_dsi *dsi = dev_get_drvdata(dev);
 
 	ret = mtk_dsi_encoder_init(drm, dsi);
+	if (ret)
+		return ret;
 
-	return ret;
+	return device_reset_optional(dev);
 }
 
 static void mtk_dsi_unbind(struct device *dev, struct device *master,
-- 
2.31.1