From 4702f3b60c12223ec3c17929a75d366293376e42 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Fri, 17 Dec 2021 01:37:46 +0100
Subject: drm: rcar-du: Add support for the nomodeset kernel parameter
Git-commit: fce8bfffa23943dfcc2339a748db4f296dc7bea7
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

According to disable Documentation/admin-guide/kernel-parameters.txt, this
parameter can be used to disable kernel modesetting.

DRM drivers will not perform display-mode changes or accelerated rendering
and only the system framebuffer will be available if it was set-up.

But only a few DRM drivers currently check for nomodeset, make this driver
to also support the command line parameter.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217003752.3946210-32-javierm@redhat.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/rcar-du/rcar_du_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index 5a8131ef81d5..982e450233ed 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -701,6 +701,9 @@ static struct platform_driver rcar_du_platform_driver = {
 
 static int __init rcar_du_init(void)
 {
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	rcar_du_of_init(rcar_du_of_table);
 
 	return platform_driver_register(&rcar_du_platform_driver);
-- 
2.38.1