Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755937AbcJTRsZ (ORCPT ); Thu, 20 Oct 2016 13:48:25 -0400 Received: from foss.arm.com ([217.140.101.70]:54280 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755810AbcJTRsU (ORCPT ); Thu, 20 Oct 2016 13:48:20 -0400 Date: Thu, 20 Oct 2016 18:48:10 +0100 From: Brian Starkey To: Gustavo Padovan 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: <20161020174810.GB7165@e106950-lin.cambridge.arm.com> References: <1476975005-30441-1-git-send-email-gustavo@padovan.org> <1476975005-30441-5-git-send-email-gustavo@padovan.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <1476975005-30441-5-git-send-email-gustavo@padovan.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10573 Lines: 340 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? 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. > /* > * 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. Thanks, Brian > /** > * @event: > * >@@ -748,6 +750,18 @@ static inline struct drm_crtc *fence_to_crtc(struct fence *fence) > } > > /** >+ * struct drm_out_fence_state - store out_fence data for install and clean up >+ * @out_fence_ptr: user pointer to store the fence fd in. >+ * @sync_file: sync_file related to the out_fence >+ * @fd: file descriptor to installed on the sync_file. >+ */ >+struct drm_out_fence_state { >+ u64 __user *out_fence_ptr; >+ struct sync_file *sync_file; >+ int fd; >+}; >+ >+/* > * struct drm_mode_set - new values for a CRTC config change > * @fb: framebuffer to use for new config > * @crtc: CRTC whose configuration we're about to change >@@ -1230,6 +1244,11 @@ struct drm_mode_config { > */ > struct drm_property *prop_in_fence_fd; > /** >+ * @prop_out_fence_ptr: Sync File fd pointer representing the >+ * outgoing fences for a CRTC. >+ */ >+ struct drm_property *prop_out_fence_ptr; >+ /** > * @prop_crtc_id: Default atomic plane property to specify the > * &drm_crtc. > */ >-- >2.5.5 > >_______________________________________________ >dri-devel mailing list >dri-devel@lists.freedesktop.org >https://lists.freedesktop.org/mailman/listinfo/dri-devel