[PATCH v5] drm/virtio: Add option to disable KMS support

[Gerd Hoffmann]

On Thu, Mar 02, 2023 at 12:39:33AM +0300, Dmitry Osipenko wrote:
> On 3/1/23 21:54, Rob Clark wrote:
> >  /* virtgpu_display.c */
> > +#if defined(CONFIG_DRM_VIRTIO_GPU_KMS)
> >  int virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev);
> >  void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev);
> > +#else
> > +static inline int virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev)
> > +{
> > +	return 0;
> > +}
> > +static inline void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev)
> > +{
> > +}
> > +#endif
> 
> In v4 Gerd wanted to keep building the virtgpu_display.o and instead add
> the KSM config check to virtio_gpu_modeset_init/fini().

The main point is that the code workflow should be the same in both
cases.  The patch does that for virtio_gpu_modeset_init() but doesn't
for virtio_gpu_modeset_fini().

Return early in the functions (and drop the #ifdef here) is how I would
implement this, but I wouldn't insist on that, there are other ways to
solve this too ;)

take care,
  Gerd