Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755365AbcJTUaY (ORCPT ); Thu, 20 Oct 2016 16:30:24 -0400 Received: from mail-vk0-f68.google.com ([209.85.213.68]:34208 "EHLO mail-vk0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755158AbcJTUaX (ORCPT ); Thu, 20 Oct 2016 16:30:23 -0400 Date: Thu, 20 Oct 2016 18:30:17 -0200 From: Gustavo Padovan To: Brian Starkey Cc: dri-devel@lists.freedesktop.org, marcheu@google.com, Daniel Stone , seanpaul@google.com, Daniel Vetter , linux-kernel@vger.kernel.org, laurent.pinchart@ideasonboard.com, Gustavo Padovan , John Harrison , m.chehab@samsung.com Subject: Re: [PATCH v5 4/4] drm/fence: add out-fences support Message-ID: <20161020203017.GC2734@joana> Mail-Followup-To: Gustavo Padovan , Brian Starkey , dri-devel@lists.freedesktop.org, marcheu@google.com, Daniel Stone , seanpaul@google.com, Daniel Vetter , linux-kernel@vger.kernel.org, laurent.pinchart@ideasonboard.com, Gustavo Padovan , John Harrison , m.chehab@samsung.com References: <1476975005-30441-1-git-send-email-gustavo@padovan.org> <1476975005-30441-5-git-send-email-gustavo@padovan.org> <20161020174810.GB7165@e106950-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161020174810.GB7165@e106950-lin.cambridge.arm.com> User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10556 Lines: 312 Hi Brian, 2016-10-20 Brian Starkey : > Hi Gustavo, > > I notice your branch has the sync_file refcount change in, but this > doesn't seem to take account for that. Will you be dropping that > change to match the semantics of fence_array? I will drop the fence_get() in the out-fence patch because we already hold the ref when we create the fence. The sync_file refcount patch will remain. > > Couple more comments below. > > On Thu, Oct 20, 2016 at 12:50:05PM -0200, Gustavo Padovan wrote: > > From: Gustavo Padovan > > > > Support DRM out-fences by creating a sync_file with a fence for each CRTC > > that sets the OUT_FENCE_PTR property. > > > > We use the out_fence pointer received in the OUT_FENCE_PTR prop to send > > the sync_file fd back to userspace. > > > > The sync_file and fd are allocated/created before commit, but the > > fd_install operation only happens after we know that commit succeed. > > > > In case of error userspace should receive a fd number of -1. > > > > v2: Comment by Rob Clark: > > - Squash commit that adds DRM_MODE_ATOMIC_OUT_FENCE flag here. > > > > Comment by Daniel Vetter: > > - Add clean up code for out_fences > > > > v3: Comments by Daniel Vetter: > > - create DRM_MODE_ATOMIC_EVENT_MASK > > - userspace should fill out_fences_ptr with the crtc_ids for which > > it wants fences back. > > > > v4: Create OUT_FENCE_PTR properties and remove old approach. > > > > Signed-off-by: Gustavo Padovan > > --- > > drivers/gpu/drm/drm_atomic.c | 116 ++++++++++++++++++++++++++++++++++--------- > > drivers/gpu/drm/drm_crtc.c | 8 +++ > > include/drm/drm_crtc.h | 19 +++++++ > > 3 files changed, 119 insertions(+), 24 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c > > index b3284b2..07775fc 100644 > > --- a/drivers/gpu/drm/drm_atomic.c > > +++ b/drivers/gpu/drm/drm_atomic.c > > @@ -490,6 +490,8 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc, > > &replaced); > > state->color_mgmt_changed |= replaced; > > return ret; > > + } else if (property == config->prop_out_fence_ptr) { > > + state->out_fence_ptr = u64_to_user_ptr(val); > > } else if (crtc->funcs->atomic_set_property) > > return crtc->funcs->atomic_set_property(crtc, state, property, val); > > else > > @@ -532,6 +534,8 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc, > > *val = (state->ctm) ? state->ctm->base.id : 0; > > else if (property == config->gamma_lut_property) > > *val = (state->gamma_lut) ? state->gamma_lut->base.id : 0; > > + else if (property == config->prop_out_fence_ptr) > > + *val = 0; > > else if (crtc->funcs->atomic_get_property) > > return crtc->funcs->atomic_get_property(crtc, state, property, val); > > else > > @@ -1474,11 +1478,9 @@ EXPORT_SYMBOL(drm_atomic_nonblocking_commit); > > */ > > > > static struct drm_pending_vblank_event *create_vblank_event( > > - struct drm_device *dev, struct drm_file *file_priv, > > - struct fence *fence, uint64_t user_data) > > + struct drm_device *dev, uint64_t user_data) > > { > > struct drm_pending_vblank_event *e = NULL; > > - int ret; > > > > e = kzalloc(sizeof *e, GFP_KERNEL); > > if (!e) > > @@ -1488,17 +1490,6 @@ static struct drm_pending_vblank_event *create_vblank_event( > > e->event.base.length = sizeof(e->event); > > e->event.user_data = user_data; > > > > - if (file_priv) { > > - ret = drm_event_reserve_init(dev, file_priv, &e->base, > > - &e->event.base); > > - if (ret) { > > - kfree(e); > > - return NULL; > > - } > > - } > > - > > - e->base.fence = fence; > > - > > return e; > > } > > > > @@ -1603,6 +1594,40 @@ void drm_atomic_clean_old_fb(struct drm_device *dev, > > } > > EXPORT_SYMBOL(drm_atomic_clean_old_fb); > > > > +static int crtc_setup_out_fence(struct drm_crtc *crtc, > > + struct drm_crtc_state *crtc_state, > > + struct drm_out_fence_state *fence_state) > > +{ > > + struct fence *fence; > > + > > + fence_state->fd = get_unused_fd_flags(O_CLOEXEC); > > + if (fence_state->fd < 0) { > > + return fence_state->fd; > > + } > > + > > + fence_state->out_fence_ptr = crtc_state->out_fence_ptr; > > + crtc_state->out_fence_ptr = NULL; > > + > > + if (put_user(fence_state->fd, fence_state->out_fence_ptr)) > > + return -EFAULT; > > + > > + fence = kzalloc(sizeof(*fence), GFP_KERNEL); > > + if (!fence) > > + return -ENOMEM; > > + > > + fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock, > > + crtc->fence_context, ++crtc->fence_seqno); > > + > > + fence_state->sync_file = sync_file_create(fence); > > + if(!fence_state->sync_file) { > > + fence_put(fence); > > + return -ENOMEM; > > + } > > + > > + crtc_state->event->base.fence = fence_get(fence); > > + return 0; > > +} > > + > > int drm_mode_atomic_ioctl(struct drm_device *dev, > > void *data, struct drm_file *file_priv) > > { > > @@ -1617,9 +1642,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > > struct drm_plane *plane; > > struct drm_crtc *crtc; > > struct drm_crtc_state *crtc_state; > > + struct drm_out_fence_state *fence_state; > > unsigned plane_mask; > > int ret = 0; > > - unsigned int i, j; > > + unsigned int i, j, fence_idx = 0; > > > > /* disallow for drivers not supporting atomic: */ > > if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) > > @@ -1734,12 +1760,19 @@ retry: > > drm_mode_object_unreference(obj); > > } > > > > - if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) { > > - for_each_crtc_in_state(state, crtc, crtc_state, i) { > > + fence_state = kcalloc(dev->mode_config.num_crtc, sizeof(*fence_state), > > + GFP_KERNEL); > > + if (!fence_state) { > > + ret = -ENOMEM; > > + goto out; > > + } > > + > > + for_each_crtc_in_state(state, crtc, crtc_state, i) { > > + if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || > > + crtc_state->out_fence_ptr) { > > struct drm_pending_vblank_event *e; > > > > - e = create_vblank_event(dev, file_priv, NULL, > > - arg->user_data); > > + e = create_vblank_event(dev, arg->user_data); > > if (!e) { > > ret = -ENOMEM; > > goto out; > > @@ -1747,6 +1780,28 @@ retry: > > > > crtc_state->event = e; > > } > > + > > + if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) { > > + struct drm_pending_vblank_event *e = crtc_state->event; > > + > > + if (!file_priv) > > + continue; > > + > > + ret = drm_event_reserve_init(dev, file_priv, &e->base, > > + &e->event.base); > > + if (ret) { > > + kfree(e); > > + crtc_state->event = NULL; > > + goto out; > > + } > > + } > > + > > + if (crtc_state->out_fence_ptr) { > > + ret = crtc_setup_out_fence(crtc, crtc_state, > > + &fence_state[fence_idx++]); > > + if (ret) > > + goto out; > > + } > > } > > > > if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) { > > @@ -1761,24 +1816,37 @@ retry: > > ret = drm_atomic_commit(state); > > } > > > > + for (i = 0; i < fence_idx; i++) > > + fd_install(fence_state[i].fd, fence_state[i].sync_file->file); > > + > > out: > > drm_atomic_clean_old_fb(dev, plane_mask, ret); > > > > - if (ret && arg->flags & DRM_MODE_PAGE_FLIP_EVENT) { > > + for_each_crtc_in_state(state, crtc, crtc_state, i) { > > I think a check on ret is still needed before you iterate the CRTCs. > If the commit is successful then state has already been freed by this > point, and I get a splat. Yes, I believe I only tested with non-blocking requests. > > > /* > > * TEST_ONLY and PAGE_FLIP_EVENT are mutually exclusive, > > * if they weren't, this code should be called on success > > * for TEST_ONLY too. > > */ > > + if (ret && crtc_state->event) > > + drm_event_cancel_free(dev, &crtc_state->event->base); > > + } > > > > - for_each_crtc_in_state(state, crtc, crtc_state, i) { > > - if (!crtc_state->event) > > - continue; > > + if (ret && fence_state) { > > + for (i = 0; i < fence_idx; i++) { > > + if (fence_state[i].fd >= 0) > > + put_unused_fd(fence_state[i].fd); > > + if (fence_state[i].sync_file) > > + fput(fence_state[i].sync_file->file); > > > > - drm_event_cancel_free(dev, &crtc_state->event->base); > > + /* If this fails, there's not much we can do about it */ > > + if (put_user(-1, fence_state->out_fence_ptr)) > > + DRM_ERROR("Couldn't clear out_fence_ptr\n"); > > } > > } > > > > + kfree(fence_state); > > + > > if (ret == -EDEADLK) { > > drm_atomic_state_clear(state); > > drm_modeset_backoff(&ctx); > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c > > index b99090f..40bce97 100644 > > --- a/drivers/gpu/drm/drm_crtc.c > > +++ b/drivers/gpu/drm/drm_crtc.c > > @@ -274,6 +274,8 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, > > if (drm_core_check_feature(dev, DRIVER_ATOMIC)) { > > drm_object_attach_property(&crtc->base, config->prop_active, 0); > > drm_object_attach_property(&crtc->base, config->prop_mode_id, 0); > > + drm_object_attach_property(&crtc->base, > > + config->prop_out_fence_ptr, 0); > > } > > > > return 0; > > @@ -434,6 +436,12 @@ static int drm_mode_create_standard_properties(struct drm_device *dev) > > return -ENOMEM; > > dev->mode_config.prop_in_fence_fd = prop; > > > > + prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC, > > + "OUT_FENCE_PTR", 0, U64_MAX); > > + if (!prop) > > + return -ENOMEM; > > + dev->mode_config.prop_out_fence_ptr = prop; > > + > > prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC, > > "CRTC_ID", DRM_MODE_OBJECT_CRTC); > > if (!prop) > > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > > index 657a33a..b898604 100644 > > --- a/include/drm/drm_crtc.h > > +++ b/include/drm/drm_crtc.h > > @@ -165,6 +165,8 @@ struct drm_crtc_state { > > struct drm_property_blob *ctm; > > struct drm_property_blob *gamma_lut; > > > > + u64 __user *out_fence_ptr; > > + > > I'm somewhat not convinced about stashing a __user pointer in the > CRTC atomic state. I know it gets cleared before the driver sees it, > but if anything I think that hints that this isn't the right place to > store it. > > I've been trying to think of other ways to get from a property to > something drm_mode_atomic_ioctl can use - maybe we can store some > stuff in drm_atomic_state which only lives for the length of the ioctl > call and put this pointer in there. The drm_atomic_state is still visible by the drivers. Between there and crtc_state, I would keep in the crtc_state for now. Gustavo