[PATCH] drm: Avoid NULL dereference of drm_device.dev

[Chris Wilson]

For a virtual device, drm_device.dev is NULL, so becareful not to
dereference it unconditionally in core code such as drm_dev_register().

Fixes: 75f6dfe3e652 ("drm: Deduplicate driver initialization message")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Gabriel Krisman Bertazi <krisman at collabora.co.uk>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_drv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 24d2949fd80b..6285e42b42da 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -767,7 +767,8 @@ int drm_dev_register(struct drm_device *dev, unsigned long 
flags)

        DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
                 driver->name, driver->major, driver->minor,
-                driver->patchlevel, driver->date, dev_name(dev->dev),
+                driver->patchlevel, driver->date,
+                dev->dev ? dev_name(dev->dev) : "virtual device",
                 dev->primary->index);

        goto out_unlock;
-- 
2.11.0