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>,
        Hyun Kwon <hyun.kwon@xilinx.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Subject: [PATCH 60/60] drm/xlnx: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 02:00:08 +0100
Message-Id: <20211215010008.2545520-61-javierm@redhat.com>
In-Reply-To: <20211215010008.2545520-1-javierm@redhat.com>
References: <20211215010008.2545520-1-javierm@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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/xlnx/zynqmp_dpsub.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dpsub.c b/drivers/gpu/drm/xlnx/zynqmp_dpsub.c
index ac37053412a1..cca55b8a8cf1 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dpsub.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dpsub.c
@@ -191,6 +191,9 @@ static int zynqmp_dpsub_probe(struct platform_device *pdev)
 	struct zynqmp_dpsub *dpsub;
 	int ret;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	/* Allocate private data. */
 	dpsub = devm_drm_dev_alloc(&pdev->dev, &zynqmp_dpsub_drm_driver,
 				   struct zynqmp_dpsub, drm);
-- 
2.33.1