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>,
        Xinliang Liu <xinliang.liu@linaro.org>
Subject: [PATCH 12/60] drm/hisilicon/hibmc: Add support for the nomodeset kernel parameter
Date:   Wed, 15 Dec 2021 01:59:20 +0100
Message-Id: <20211215010008.2545520-13-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>
Patch-cc:Tian Tao <tiantao6@hisilicon.com>
---

 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
index 610fc8e135f9..f66de93831c6 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
@@ -315,6 +315,9 @@ static int hibmc_pci_probe(struct pci_dev *pdev,
 	struct drm_device *dev;
 	int ret;
 
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &hibmc_driver);
 	if (ret)
 		return ret;
-- 
2.33.1