> +#ifdef CONFIG_LINUX > +void virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res)
> +#else > +void *virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res) > +{ > + /* nothing (stub) */ > + return NULL > +} Fails to build for !linux ... You can place the stubs in a file in the stubs/ directory instead. They'll be used via weak symbol references instead of #ifdefs then. Advantage: the stubs are compiled unconditionally so errors like this don't go unnoticed that easily. take care, Gerd