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>,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Subject: [PATCH 59/60] drm/xen: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 02:00:07 +0100
Message-Id: <20211215010008.2545520-60-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/xen/xen_drm_front.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
index 434064c820e8..20d11ea79e0f 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -495,6 +495,9 @@ static int xen_drm_drv_init(struct xen_drm_front_info *front_info)
 	struct drm_device *drm_dev;
 	int ret;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	DRM_INFO("Creating %s\n", xen_drm_driver.desc);
 
 	drm_info = kzalloc(sizeof(*drm_info), GFP_KERNEL);
-- 
2.33.1