From: Rob Clark Date: Tue, 25 Nov 2014 17:41:18 +0000 (-0500) Subject: drm/msm: block incoming update on pending updates X-Git-Tag: v4.13~6030^2~6^2~3 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=f86afecf0defbc8d046bc7a7c5fc19a8c9ba1364;p=mirror_ubuntu-bionic-kernel.git 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: Rob Clark --- diff --git a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c index a7672e100d8b..3449213f1e76 100644 --- a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c +++ b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c @@ -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); diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c index 0e9a2e3a82d7..930bcec7067f 100644 --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c @@ -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); diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c index f0de412e13dc..191968256c58 100644 --- a/drivers/gpu/drm/msm/msm_atomic.c +++ b/drivers/gpu/drm/msm/msm_atomic.c @@ -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 diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index d3b791b7ddef..7e1c71e51cb4 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -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); diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h index 136303818436..b69ef2d5a26c 100644 --- a/drivers/gpu/drm/msm/msm_drv.h +++ b/drivers/gpu/drm/msm/msm_drv.h @@ -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];