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>,
        Brian Starkey <brian.starkey@arm.com>,
        Liviu Dudau <liviu.dudau@arm.com>
Subject: [PATCH 02/60] drm/arm/hdlcd: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 01:59:10 +0100
Message-Id: <20211215010008.2545520-3-javierm@redhat.com>
In-Reply-To: <20211215010008.2545520-1-javierm@redhat.com>
References: <20211215010008.2545520-1-javierm@redhat.com>
MIME-Version: 1.0
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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/arm/hdlcd_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
index 479c2422a2e0..0939a64a9bd2 100644
--- a/drivers/gpu/drm/arm/hdlcd_drv.c
+++ b/drivers/gpu/drm/arm/hdlcd_drv.c
@@ -382,6 +382,9 @@ static int hdlcd_probe(struct platform_device *pdev)
 	struct device_node *port;
 	struct component_match *match = NULL;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	/* there is only one output port inside each device, find it */
 	port = of_graph_get_remote_node(pdev->dev.of_node, 0, 0);
 	if (!port)
-- 
2.33.1