Commit f86afecf authored by Rob Clark's avatar Rob Clark

drm/msm: block incoming update on pending updates

We can't have multiple updates pending on a given CRTC, and we don't
want a sync update to race w/ an async update that preceeded it.  So
keep track of which CRTCs have updates in flight, and block later
updates that would conflict.
Signed-off-by: default avatarRob Clark <robdclark@gmail.com>
parent 5acb07ea
......@@ -331,17 +331,8 @@ static int mdp4_crtc_atomic_check(struct drm_crtc *crtc,
struct drm_crtc_state *state)
{
struct mdp4_crtc *mdp4_crtc = to_mdp4_crtc(crtc);
struct drm_device *dev = crtc->dev;
DBG("%s: check", mdp4_crtc->name);
if (mdp4_crtc->event) {
dev_err(dev->dev, "already pending flip!\n");
return -EBUSY;
}
// TODO anything else to check?
return 0;
}
......@@ -357,7 +348,7 @@ static void mdp4_crtc_atomic_flush(struct drm_crtc *crtc)
struct drm_device *dev = crtc->dev;
unsigned long flags;
DBG("%s: flush", mdp4_crtc->name);
DBG("%s: event: %p", mdp4_crtc->name, crtc->state->event);
WARN_ON(mdp4_crtc->event);
......
......@@ -303,11 +303,6 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc,
DBG("%s: check", mdp5_crtc->name);
if (mdp5_crtc->event) {
dev_err(dev->dev, "already pending flip!\n");
return -EBUSY;
}
/* request a free CTL, if none is already allocated for this CRTC */
if (state->enable && !mdp5_crtc->ctl) {
mdp5_crtc->ctl = mdp5_ctlm_request(mdp5_kms->ctlm, crtc);
......@@ -364,7 +359,7 @@ static void mdp5_crtc_atomic_flush(struct drm_crtc *crtc)
struct drm_device *dev = crtc->dev;
unsigned long flags;
DBG("%s: flush", mdp5_crtc->name);
DBG("%s: event: %p", mdp5_crtc->name, crtc->state->event);
WARN_ON(mdp5_crtc->event);
......
......@@ -23,10 +23,41 @@ struct msm_commit {
struct drm_atomic_state *state;
uint32_t fence;
struct msm_fence_cb fence_cb;
uint32_t crtc_mask;
};
static void fence_cb(struct msm_fence_cb *cb);
/* block until specified crtcs are no longer pending update, and
* atomically mark them as pending update
*/
static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
{
int ret;
spin_lock(&priv->pending_crtcs_event.lock);
ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
!(priv->pending_crtcs & crtc_mask));
if (ret == 0) {
DBG("start: %08x", crtc_mask);
priv->pending_crtcs |= crtc_mask;
}
spin_unlock(&priv->pending_crtcs_event.lock);
return ret;
}
/* clear specified crtcs (no longer pending update)
*/
static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
{
spin_lock(&priv->pending_crtcs_event.lock);
DBG("end: %08x", crtc_mask);
priv->pending_crtcs &= ~crtc_mask;
wake_up_all_locked(&priv->pending_crtcs_event);
spin_unlock(&priv->pending_crtcs_event.lock);
}
static struct msm_commit *new_commit(struct drm_atomic_state *state)
{
struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
......@@ -58,12 +89,27 @@ static void complete_commit(struct msm_commit *c)
drm_atomic_helper_commit_post_planes(dev, state);
/* NOTE: _wait_for_vblanks() only waits for vblank on
* enabled CRTCs. So we end up faulting when disabling
* due to (potentially) unref'ing the outgoing fb's
* before the vblank when the disable has latched.
*
* But if it did wait on disabled (or newly disabled)
* CRTCs, that would be racy (ie. we could have missed
* the irq. We need some way to poll for pipe shut
* down. Or just live with occasionally hitting the
* timeout in the CRTC disable path (which really should
* not be critical path)
*/
drm_atomic_helper_wait_for_vblanks(dev, state);
drm_atomic_helper_cleanup_planes(dev, state);
drm_atomic_state_free(state);
end_atomic(dev->dev_private, c->crtc_mask);
kfree(c);
}
......@@ -97,8 +143,9 @@ static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
int msm_atomic_commit(struct drm_device *dev,
struct drm_atomic_state *state, bool async)
{
struct msm_commit *c;
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);
......@@ -106,6 +153,18 @@ int msm_atomic_commit(struct drm_device *dev,
return ret;
c = new_commit(state);
if (!c)
return -ENOMEM;
/*
* 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:
......@@ -121,6 +180,14 @@ int msm_atomic_commit(struct drm_device *dev,
add_fb(c, new_state->fb);
}
/*
* 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)
return ret;
/*
* 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
......
......@@ -193,6 +193,7 @@ static int msm_load(struct drm_device *dev, unsigned long flags)
priv->wq = alloc_ordered_workqueue("msm", 0);
init_waitqueue_head(&priv->fence_event);
init_waitqueue_head(&priv->pending_crtcs_event);
INIT_LIST_HEAD(&priv->inactive_list);
INIT_LIST_HEAD(&priv->fence_cbs);
......
......@@ -96,6 +96,10 @@ struct msm_drm_private {
/* callbacks deferred until bo is inactive: */
struct list_head fence_cbs;
/* crtcs pending async atomic updates: */
uint32_t pending_crtcs;
wait_queue_head_t pending_crtcs_event;
/* registered MMUs: */
unsigned int num_mmus;
struct msm_mmu *mmus[NUM_DOMAINS];
......
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