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>,
        Philippe Cornu <philippe.cornu@foss.st.com>,
        Yannick Fertre <yannick.fertre@foss.st.com>
Subject: [PATCH 39/60] drm/stm: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 01:59:47 +0100
Message-Id: <20211215010008.2545520-40-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/stm/drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
index 222869b232ae..91ac5437fa40 100644
--- a/drivers/gpu/drm/stm/drv.c
+++ b/drivers/gpu/drm/stm/drv.c
@@ -183,6 +183,9 @@ static int stm_drm_platform_probe(struct platform_device *pdev)
 
 	DRM_DEBUG("%s\n", __func__);
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
 
 	ddev = drm_dev_alloc(&drv_driver, dev);
-- 
2.33.1