From 1d11c39a4ffc73f09ed474d12591d186113a95b7 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Fri, 17 Dec 2021 01:37:49 +0100
Subject: drm/sti: Add support for the nomodeset kernel parameter
Git-commit: 89ec0023200e20ab4f601aaae1e457a0026209bc
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/20211217003752.3946210-35-javierm@redhat.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/sti/sti_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c
index c7efb43b83ee..860b2230aa08 100644
--- a/drivers/gpu/drm/sti/sti_drv.c
+++ b/drivers/gpu/drm/sti/sti_drv.c
@@ -287,6 +287,9 @@ static struct platform_driver * const drivers[] = {
 
 static int sti_drm_init(void)
 {
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
 }
 module_init(sti_drm_init);
-- 
2.38.1