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>,
        Boris Brezillon <bbrezillon@kernel.org>,
        Sam Ravnborg <sam@ravnborg.org>
Subject: [PATCH 06/60] drm/atmel-hlcdc: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 01:59:14 +0100
Message-Id: <20211215010008.2545520-7-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/atmel-hlcdc/atmel_hlcdc_dc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 1656d27b78b6..4637177184ce 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -747,6 +747,9 @@ static int atmel_hlcdc_dc_drm_probe(struct platform_device *pdev)
 	struct drm_device *ddev;
 	int ret;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	ddev = drm_dev_alloc(&atmel_hlcdc_dc_driver, &pdev->dev);
 	if (IS_ERR(ddev))
 		return PTR_ERR(ddev);
-- 
2.33.1