From aff2299e0d81b26304ccc6a1ec0170e437f38efc Mon Sep 17 00:00:00 2001
From: Jeremy Cline <jcline@redhat.com>
Date: Wed, 25 Nov 2020 15:26:46 -0500
Subject: [PATCH] drm/nouveau: use drm_dev_unplug() during device removal
Git-commit: aff2299e0d81b26304ccc6a1ec0170e437f38efc
Patch-mainline: v5.16-rc1
References: CVE-2020-27820 bsc#1179599

Nouveau does not currently support hot-unplugging, but it still makes
sense to switch from drm_dev_unregister() to drm_dev_unplug().
drm_dev_unplug() calls drm_dev_unregister() after marking the device as
unplugged, but only after any device critical sections are finished.

Since nouveau isn't using drm_dev_enter() and drm_dev_exit(), there are
no critical sections so this is nearly functionally equivalent. However,
the DRM layer does check to see if the device is unplugged, and if it is
returns appropriate error codes.

In the future nouveau can add critical sections in order to truly
support hot-unplugging.

Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Tested-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201125202648.5220-2-jcline@redhat.com
Link: https://gitlab.freedesktop.org/drm/nouveau/-/merge_requests/14
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/nouveau/nouveau_drm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -678,7 +678,7 @@ nouveau_drm_device_remove(struct drm_dev
 	struct nvkm_client *client;
 	struct nvkm_device *device;
 
-	drm_dev_unregister(dev);
+	drm_dev_unplug(dev);
 
 	dev->irq_enabled = false;
 	client = nvxx_client(&drm->client.base);