/* Public domain. */

#include <linux/kernel.h>

#include <drm/drm_plane.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_atomic_uapi.h>
#include <drm/drm_gem.h>
#include <linux/dma-resv.h>

int
drm_gem_plane_helper_prepare_fb(struct drm_plane *dp,
    struct drm_plane_state *dps)
{
        struct drm_gem_object *obj;
        struct dma_fence *f;
        int r;

        if (dps->fb != NULL) {
                obj = dps->fb->obj[0];
                if (obj == NULL)
                        return -EINVAL;
                r = dma_resv_get_singleton(obj->resv, DMA_RESV_USAGE_WRITE, &f);
                if (r)
                        return r;
                if (dps->fence)
                        dma_fence_put(f);
                else
                        dps->fence = f;
        }

        return 0;
}