From 2d99ced787e3d0f251fa370d2aae83cf2085a8d9 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Thu, 29 Aug 2019 09:45:16 -0700 Subject: drm/msm: async commit support Now that flush/wait/complete is decoupled from the "synchronous" part of atomic commit_tail(), add support to defer flush to a timer that expires shortly before vblank for async commits. In this way, multiple atomic commits (for example, cursor updates) can be coalesced into a single flush at the end of the frame. v2: don't hold lock over ->wait_flush(), to avoid locking interaction that was causing fps drop when combining page flips or non-async atomic commits and lots of legacy cursor updates Signed-off-by: Rob Clark Reviewed-by: Sean Paul --- drivers/gpu/drm/msm/msm_atomic.c | 156 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 155 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/msm/msm_atomic.c') diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c index 517d3a747778..55c8d72f8401 100644 --- a/drivers/gpu/drm/msm/msm_atomic.c +++ b/drivers/gpu/drm/msm/msm_atomic.c @@ -26,6 +26,95 @@ int msm_atomic_prepare_fb(struct drm_plane *plane, return msm_framebuffer_prepare(new_state->fb, kms->aspace); } +static void msm_atomic_async_commit(struct msm_kms *kms, int crtc_idx) +{ + unsigned crtc_mask = BIT(crtc_idx); + + mutex_lock(&kms->commit_lock); + + if (!(kms->pending_crtc_mask & crtc_mask)) { + mutex_unlock(&kms->commit_lock); + return; + } + + kms->pending_crtc_mask &= ~crtc_mask; + + kms->funcs->enable_commit(kms); + + /* + * Flush hardware updates: + */ + DRM_DEBUG_ATOMIC("triggering async commit\n"); + kms->funcs->flush_commit(kms, crtc_mask); + mutex_unlock(&kms->commit_lock); + + /* + * Wait for flush to complete: + */ + kms->funcs->wait_flush(kms, crtc_mask); + + mutex_lock(&kms->commit_lock); + kms->funcs->complete_commit(kms, crtc_mask); + mutex_unlock(&kms->commit_lock); + kms->funcs->disable_commit(kms); +} + +static enum hrtimer_restart msm_atomic_pending_timer(struct hrtimer *t) +{ + struct msm_pending_timer *timer = container_of(t, + struct msm_pending_timer, timer); + struct msm_drm_private *priv = timer->kms->dev->dev_private; + + queue_work(priv->wq, &timer->work); + + return HRTIMER_NORESTART; +} + +static void msm_atomic_pending_work(struct work_struct *work) +{ + struct msm_pending_timer *timer = container_of(work, + struct msm_pending_timer, work); + + msm_atomic_async_commit(timer->kms, timer->crtc_idx); +} + +void msm_atomic_init_pending_timer(struct msm_pending_timer *timer, + struct msm_kms *kms, int crtc_idx) +{ + timer->kms = kms; + timer->crtc_idx = crtc_idx; + hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + timer->timer.function = msm_atomic_pending_timer; + INIT_WORK(&timer->work, msm_atomic_pending_work); +} + +static bool can_do_async(struct drm_atomic_state *state, + struct drm_crtc **async_crtc) +{ + struct drm_connector_state *connector_state; + struct drm_connector *connector; + struct drm_crtc_state *crtc_state; + struct drm_crtc *crtc; + int i, num_crtcs = 0; + + if (!(state->legacy_cursor_update || state->async_update)) + return false; + + /* any connector change, means slow path: */ + for_each_new_connector_in_state(state, connector, connector_state, i) + return false; + + for_each_new_crtc_in_state(state, crtc, crtc_state, i) { + if (drm_atomic_crtc_needs_modeset(crtc_state)) + return false; + if (++num_crtcs > 1) + return false; + *async_crtc = crtc; + } + + return true; +} + /* Get bitmask of crtcs that will need to be flushed. The bitmask * can be used with for_each_crtc_mask() iterator, to iterate * effected crtcs without needing to preserve the atomic state. @@ -47,9 +136,25 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state) struct drm_device *dev = state->dev; struct msm_drm_private *priv = dev->dev_private; struct msm_kms *kms = priv->kms; + struct drm_crtc *async_crtc = NULL; unsigned crtc_mask = get_crtc_mask(state); + bool async = kms->funcs->vsync_time && + can_do_async(state, &async_crtc); kms->funcs->enable_commit(kms); + + /* + * Ensure any previous (potentially async) commit has + * completed: + */ + kms->funcs->wait_flush(kms, crtc_mask); + + mutex_lock(&kms->commit_lock); + + /* + * Now that there is no in-progress flush, prepare the + * current update: + */ kms->funcs->prepare_commit(kms, state); /* @@ -59,6 +164,49 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state) drm_atomic_helper_commit_planes(dev, state, 0); drm_atomic_helper_commit_modeset_enables(dev, state); + if (async) { + struct msm_pending_timer *timer = + &kms->pending_timers[drm_crtc_index(async_crtc)]; + + /* async updates are limited to single-crtc updates: */ + WARN_ON(crtc_mask != drm_crtc_mask(async_crtc)); + + /* + * Start timer if we don't already have an update pending + * on this crtc: + */ + if (!(kms->pending_crtc_mask & crtc_mask)) { + ktime_t vsync_time, wakeup_time; + + kms->pending_crtc_mask |= crtc_mask; + + vsync_time = kms->funcs->vsync_time(kms, async_crtc); + wakeup_time = ktime_sub(vsync_time, ms_to_ktime(1)); + + hrtimer_start(&timer->timer, wakeup_time, + HRTIMER_MODE_ABS); + } + + kms->funcs->disable_commit(kms); + mutex_unlock(&kms->commit_lock); + + /* + * At this point, from drm core's perspective, we + * are done with the atomic update, so we can just + * go ahead and signal that it is done: + */ + drm_atomic_helper_commit_hw_done(state); + drm_atomic_helper_cleanup_planes(dev, state); + + return; + } + + /* + * If there is any async flush pending on updated crtcs, fold + * them into the current flush. + */ + kms->pending_crtc_mask &= ~crtc_mask; + /* * Flush hardware updates: */ @@ -67,12 +215,18 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state) kms->funcs->commit(kms, state); } kms->funcs->flush_commit(kms, crtc_mask); + mutex_unlock(&kms->commit_lock); + /* + * Wait for flush to complete: + */ kms->funcs->wait_flush(kms, crtc_mask); + + mutex_lock(&kms->commit_lock); kms->funcs->complete_commit(kms, crtc_mask); + mutex_unlock(&kms->commit_lock); kms->funcs->disable_commit(kms); drm_atomic_helper_commit_hw_done(state); - drm_atomic_helper_cleanup_planes(dev, state); } -- cgit v1.2.3-59-g8ed1b