2 * Copyright (C) 2014 Red Hat
3 * Author: Rob Clark <robdclark@gmail.com>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * You should have received a copy of the GNU General Public License along with
15 * this program. If not, see <http://www.gnu.org/licenses/>.
23 struct drm_atomic_state *state;
25 struct msm_fence_cb fence_cb;
29 static void fence_cb(struct msm_fence_cb *cb);
31 /* block until specified crtcs are no longer pending update, and
32 * atomically mark them as pending update
34 static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
38 spin_lock(&priv->pending_crtcs_event.lock);
39 ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
40 !(priv->pending_crtcs & crtc_mask));
42 DBG("start: %08x", crtc_mask);
43 priv->pending_crtcs |= crtc_mask;
45 spin_unlock(&priv->pending_crtcs_event.lock);
50 /* clear specified crtcs (no longer pending update)
52 static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
54 spin_lock(&priv->pending_crtcs_event.lock);
55 DBG("end: %08x", crtc_mask);
56 priv->pending_crtcs &= ~crtc_mask;
57 wake_up_all_locked(&priv->pending_crtcs_event);
58 spin_unlock(&priv->pending_crtcs_event.lock);
61 static struct msm_commit *new_commit(struct drm_atomic_state *state)
63 struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
69 /* TODO we might need a way to indicate to run the cb on a
70 * different wq so wait_for_vblanks() doesn't block retiring
73 INIT_FENCE_CB(&c->fence_cb, fence_cb);
78 /* The (potentially) asynchronous part of the commit. At this point
79 * nothing can fail short of armageddon.
81 static void complete_commit(struct msm_commit *c)
83 struct drm_atomic_state *state = c->state;
84 struct drm_device *dev = state->dev;
86 drm_atomic_helper_commit_pre_planes(dev, state);
88 drm_atomic_helper_commit_planes(dev, state);
90 drm_atomic_helper_commit_post_planes(dev, state);
92 /* NOTE: _wait_for_vblanks() only waits for vblank on
93 * enabled CRTCs. So we end up faulting when disabling
94 * due to (potentially) unref'ing the outgoing fb's
95 * before the vblank when the disable has latched.
97 * But if it did wait on disabled (or newly disabled)
98 * CRTCs, that would be racy (ie. we could have missed
99 * the irq. We need some way to poll for pipe shut
100 * down. Or just live with occasionally hitting the
101 * timeout in the CRTC disable path (which really should
102 * not be critical path)
105 drm_atomic_helper_wait_for_vblanks(dev, state);
107 drm_atomic_helper_cleanup_planes(dev, state);
109 drm_atomic_state_free(state);
111 end_atomic(dev->dev_private, c->crtc_mask);
116 static void fence_cb(struct msm_fence_cb *cb)
118 struct msm_commit *c =
119 container_of(cb, struct msm_commit, fence_cb);
123 static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
125 struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0);
126 c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ));
130 int msm_atomic_check(struct drm_device *dev,
131 struct drm_atomic_state *state)
136 * msm ->atomic_check can update ->mode_changed for pixel format
137 * changes, hence must be run before we check the modeset changes.
139 ret = drm_atomic_helper_check_planes(dev, state);
143 ret = drm_atomic_helper_check_modeset(dev, state);
151 * drm_atomic_helper_commit - commit validated state object
153 * @state: the driver state object
154 * @async: asynchronous commit
156 * This function commits a with drm_atomic_helper_check() pre-validated state
157 * object. This can still fail when e.g. the framebuffer reservation fails. For
158 * now this doesn't implement asynchronous commits.
161 * Zero for success or -errno.
163 int msm_atomic_commit(struct drm_device *dev,
164 struct drm_atomic_state *state, bool async)
166 int nplanes = dev->mode_config.num_total_plane;
167 int ncrtcs = dev->mode_config.num_crtc;
168 struct msm_commit *c;
171 ret = drm_atomic_helper_prepare_planes(dev, state);
175 c = new_commit(state);
180 * Figure out what crtcs we have:
182 for (i = 0; i < ncrtcs; i++) {
183 struct drm_crtc *crtc = state->crtcs[i];
186 c->crtc_mask |= (1 << drm_crtc_index(crtc));
190 * Figure out what fence to wait for:
192 for (i = 0; i < nplanes; i++) {
193 struct drm_plane *plane = state->planes[i];
194 struct drm_plane_state *new_state = state->plane_states[i];
199 if ((plane->state->fb != new_state->fb) && new_state->fb)
200 add_fb(c, new_state->fb);
204 * Wait for pending updates on any of the same crtc's and then
205 * mark our set of crtc's as busy:
207 ret = start_atomic(dev->dev_private, c->crtc_mask);
212 * This is the point of no return - everything below never fails except
213 * when the hw goes bonghits. Which means we can commit the new state on
214 * the software side now.
217 drm_atomic_helper_swap_state(dev, state);
220 * Everything below can be run asynchronously without the need to grab
221 * any modeset locks at all under one conditions: It must be guaranteed
222 * that the asynchronous work has either been cancelled (if the driver
223 * supports it, which at least requires that the framebuffers get
224 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
225 * before the new state gets committed on the software side with
226 * drm_atomic_helper_swap_state().
228 * This scheme allows new atomic state updates to be prepared and
229 * checked in parallel to the asynchronous completion of the previous
230 * update. Which is important since compositors need to figure out the
231 * composition of the next frame right after having submitted the
236 msm_queue_fence_cb(dev, &c->fence_cb, c->fence);
240 ret = msm_wait_fence_interruptable(dev, c->fence, NULL);
242 WARN_ON(ret); // TODO unswap state back? or??