drm/virtio: Fix driver removal with disabled KMS

DRM atomic and modesetting aren't initialized if virtio-gpu driver built
with disabled KMS, leading to access of uninitialized data on driver
removal/unbinding and crashing kernel. Fix it by skipping shutting down
atomic core with unavailable KMS.

Fixes: 72122c69d717 ("drm/virtio: Add option to disable KMS support")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
Reviewed-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
Link: https://patch.msgid.link/20260604122743.13383-1-dmitry.osipenko@collabora.com

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index a5ce96fb8a1d24cff29c00706637834dc214c95e..9af740bda835936913b1c7c83314b501deac2ba4 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -124,7 +124,10 @@ static void virtio_gpu_remove(struct virtio_device *vdev)
        struct drm_device *dev = vdev->priv;
 
        drm_dev_unplug(dev);
-       drm_atomic_helper_shutdown(dev);
+
+       if (drm_core_check_feature(dev, DRIVER_ATOMIC))
+               drm_atomic_helper_shutdown(dev);
+
        virtio_gpu_deinit(dev);
        drm_dev_put(dev);
 }