From:   Javier Martinez Canillas <javierm@redhat.com>
To:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Cc:     Javier Martinez Canillas <javierm@redhat.com>,
        Hans de Goede <hdegoede@redhat.com>
Subject: [PATCH 46/60] drm/gm12u320: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 01:59:54 +0100
Message-Id: <20211215010008.2545520-47-javierm@redhat.com>
In-Reply-To: <20211215010008.2545520-1-javierm@redhat.com>
References: <20211215010008.2545520-1-javierm@redhat.com>
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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 systewm 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>
---

 drivers/gpu/drm/tiny/gm12u320.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/tiny/gm12u320.c b/drivers/gpu/drm/tiny/gm12u320.c
index 6bc0c298739c..b9a5f4969337 100644
--- a/drivers/gpu/drm/tiny/gm12u320.c
+++ b/drivers/gpu/drm/tiny/gm12u320.c
@@ -636,6 +636,9 @@ static int gm12u320_usb_probe(struct usb_interface *interface,
 	struct drm_device *dev;
 	int ret;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	/*
 	 * The gm12u320 presents itself to the system as 2 usb mass-storage
 	 * interfaces, we only care about / need the first one.
-- 
2.33.1