/**
* drm_gem_fb_prepare_fb() - Prepare a GEM backed framebuffer
* @plane: Plane
* @state: Plane state the fence will be attached to
*
* This function prepares a GEM backed framebuffer for scanout by checking if
* the plane framebuffer has a DMA-BUF attached. If it does, it extracts the
* exclusive fence and attaches it to the plane state for the atomic helper to
* wait on. This function can be used as the &drm_plane_helper_funcs.prepare_fb
* callback.
*
* There is no need for &drm_plane_helper_funcs.cleanup_fb hook for simple
* gem based framebuffer drivers which have their buffers always pinned in
* memory.
*/
int drm_gem_fb_prepare_fb(struct drm_plane *plane,
struct drm_plane_state *state)
{
struct dma_buf *dma_buf;
struct dma_fence *fence;
if (!state->fb)
return 0;
dma_buf = drm_gem_fb_get_obj(state->fb, 0)->dma_buf;
if (dma_buf) {
fence = reservation_object_get_excl_rcu(dma_buf->resv);
drm_atomic_set_fence_for_plane(state, fence);
}
return 0;
}
int msm_atomic_prepare_fb(struct drm_plane *plane,
struct drm_plane_state *new_state)
{
struct msm_drm_private *priv = plane->dev->dev_private;
struct msm_kms *kms = priv->kms;
struct drm_gem_object *obj;
struct msm_gem_object *msm_obj;
struct dma_fence *fence;
if (!new_state->fb)
return 0;
obj = msm_framebuffer_bo(new_state->fb, 0);
msm_obj = to_msm_bo(obj);
fence = reservation_object_get_excl_rcu(msm_obj->resv);
drm_atomic_set_fence_for_plane(new_state, fence);
return msm_framebuffer_prepare(new_state->fb, kms->aspace);
}
/**
* drm_atomic_helper_commit - commit validated state object
* @dev: DRM device
* @state: the driver state object
* @nonblock: nonblocking commit
*
* This function commits a with drm_atomic_helper_check() pre-validated state
* object. This can still fail when e.g. the framebuffer reservation fails.
*
* RETURNS
* Zero for success or -errno.
*/
int msm_atomic_commit(struct drm_device *dev,
struct drm_atomic_state *state, bool nonblock)
{
struct msm_drm_private *priv = dev->dev_private;
int nplanes = dev->mode_config.num_total_plane;
int ncrtcs = dev->mode_config.num_crtc;
struct msm_commit *c;
int i, ret;
ret = drm_atomic_helper_prepare_planes(dev, state);
if (ret)
return ret;
c = commit_init(state);
if (!c) {
ret = -ENOMEM;
goto error;
}
/*
* Figure out what crtcs we have:
*/
for (i = 0; i < ncrtcs; i++) {
struct drm_crtc *crtc = state->crtcs[i];
if (!crtc)
continue;
c->crtc_mask |= (1 << drm_crtc_index(crtc));
}
/*
* Figure out what fence to wait for:
*/
for (i = 0; i < nplanes; i++) {
struct drm_plane *plane = state->planes[i];
struct drm_plane_state *new_state = state->plane_states[i];
if (!plane)
continue;
if ((plane->state->fb != new_state->fb) && new_state->fb) {
struct drm_gem_object *obj = msm_framebuffer_bo(new_state->fb, 0);
struct msm_gem_object *msm_obj = to_msm_bo(obj);
new_state->fence = reservation_object_get_excl_rcu(msm_obj->resv);
}
}
/*
* Wait for pending updates on any of the same crtc's and then
* mark our set of crtc's as busy:
*/
ret = start_atomic(dev->dev_private, c->crtc_mask);
if (ret) {
kfree(c);
goto error;
}
/*
* This is the point of no return - everything below never fails except
* when the hw goes bonghits. Which means we can commit the new state on
* the software side now.
*/
drm_atomic_helper_swap_state(dev, state);
/*
* Everything below can be run asynchronously without the need to grab
* any modeset locks at all under one conditions: It must be guaranteed
* that the asynchronous work has either been cancelled (if the driver
* supports it, which at least requires that the framebuffers get
* cleaned up with drm_atomic_helper_cleanup_planes()) or completed
* before the new state gets committed on the software side with
* drm_atomic_helper_swap_state().
*
* This scheme allows new atomic state updates to be prepared and
* checked in parallel to the asynchronous completion of the previous
* update. Which is important since compositors need to figure out the
* composition of the next frame right after having submitted the
* current layout.
*/
if (nonblock) {
queue_work(priv->atomic_wq, &c->work);
return 0;
}
complete_commit(c, false);
return 0;
error:
drm_atomic_helper_cleanup_planes(dev, state);
return ret;
}
