Hi guys, I've a couple questions.
On 9 March 2018 at 14:49, Gustavo Padovan <gust...@padovan.org> wrote: > From: Gustavo Padovan <gustavo.pado...@collabora.com> > > If V4L2_BUF_FLAG_OUT_FENCE flag is present on the QBUF call we create > an out_fence and send its fd to userspace on the fence_fd field as a > return arg for the QBUF call. > > The fence is signaled on buffer_done(), when the job on the buffer is > finished. > > v9: - remove in-fences changes from this patch (Alex Courbot) > - improve fence context creation (Hans Verkuil) > - clean up out fences if vb2_core_qbuf() fails (Hans Verkuil) > > v8: > - return 0 as fence_fd if OUT_FENCE flag not used (Mauro) > - fix crash when checking not using fences in vb2_buffer_done() > > v7: > - merge patch that add the infrastructure to out-fences into > this one (Alex Courbot) > - Do not install the fd if there is no fence. (Alex Courbot) > - do not report error on requeueing, just WARN_ON_ONCE() (Hans) > > v6 > - get rid of the V4L2_EVENT_OUT_FENCE event. We always keep the > ordering in vb2 for queueing in the driver, so the event is not > necessary anymore and the out_fence_fd is sent back to userspace > on QBUF call return arg > - do not allow requeueing with out-fences, instead mark the buffer > with an error and wake up to userspace. > - send the out_fence_fd back to userspace on the fence_fd field > > v5: > - delay fd_install to DQ_EVENT (Hans) > - if queue is fully ordered send OUT_FENCE event right away > (Brian) > - rename 'q->ordered' to 'q->ordered_in_driver' > - merge change to implement OUT_FENCE event here > > v4: > - return the out_fence_fd in the BUF_QUEUED event(Hans) > > v3: - add WARN_ON_ONCE(q->ordered) on requeueing (Hans) > - set the OUT_FENCE flag if there is a fence pending (Hans) > - call fd_install() after vb2_core_qbuf() (Hans) > - clean up fence if vb2_core_qbuf() fails (Hans) > - add list to store sync_file and fence for the next queued buffer > > v2: check if the queue is ordered. > > Signed-off-by: Gustavo Padovan <gustavo.pado...@collabora.com> > --- > drivers/media/common/videobuf2/videobuf2-core.c | 88 > +++++++++++++++++++++++++ > drivers/media/common/videobuf2/videobuf2-v4l2.c | 20 +++++- > include/media/videobuf2-core.h | 25 +++++++ > 3 files changed, 132 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c > b/drivers/media/common/videobuf2/videobuf2-core.c > index 5de5e35cfc40..dd18a9f345c7 100644 > --- a/drivers/media/common/videobuf2/videobuf2-core.c > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > @@ -25,6 +25,7 @@ > #include <linux/sched.h> > #include <linux/freezer.h> > #include <linux/kthread.h> > +#include <linux/sync_file.h> > > #include <media/videobuf2-core.h> > #include <media/v4l2-mc.h> > @@ -357,6 +358,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum > vb2_memory memory, > vb->planes[plane].length = plane_sizes[plane]; > vb->planes[plane].min_length = plane_sizes[plane]; > } > + vb->out_fence_fd = -1; > q->bufs[vb->index] = vb; > > /* Allocate video buffer memory for the MMAP type */ > @@ -934,10 +936,22 @@ static void vb2_process_buffer_done(struct vb2_buffer > *vb, enum vb2_buffer_state > case VB2_BUF_STATE_QUEUED: > return; > case VB2_BUF_STATE_REQUEUEING: > + /* Requeuing with explicit synchronization, spit warning */ > + WARN_ON_ONCE(vb->out_fence); > + > if (q->start_streaming_called) > __enqueue_in_driver(vb); > return; > default: > + if (vb->out_fence) { > + if (state == VB2_BUF_STATE_ERROR) > + dma_fence_set_error(vb->out_fence, -EFAULT); > + dma_fence_signal(vb->out_fence); > + dma_fence_put(vb->out_fence); > + vb->out_fence = NULL; > + vb->out_fence_fd = -1; > + } > + > /* Inform any processes that may be waiting for buffers */ > wake_up(&q->done_wq); > break; > @@ -1353,6 +1367,62 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned > int index, void *pb) > } > EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); > > +static inline const char *vb2_fence_get_driver_name(struct dma_fence *fence) > +{ > + return "vb2_fence"; > +} > + > +static inline const char *vb2_fence_get_timeline_name(struct dma_fence > *fence) > +{ > + return "vb2_fence_timeline"; > +} > + > +static inline bool vb2_fence_enable_signaling(struct dma_fence *fence) > +{ > + return true; > +} > + > +static const struct dma_fence_ops vb2_fence_ops = { > + .get_driver_name = vb2_fence_get_driver_name, > + .get_timeline_name = vb2_fence_get_timeline_name, > + .enable_signaling = vb2_fence_enable_signaling, > + .wait = dma_fence_default_wait, > +}; > + > +int vb2_setup_out_fence(struct vb2_queue *q, unsigned int index) > +{ > + struct vb2_buffer *vb; > + > + vb = q->bufs[index]; > + > + vb->out_fence_fd = get_unused_fd_flags(O_CLOEXEC); > + > + if (call_qop(q, is_unordered, q) || !q->queueing_started) > + q->out_fence_context = dma_fence_context_alloc(1); > + > + vb->out_fence = kzalloc(sizeof(*vb->out_fence), GFP_KERNEL); > + if (!vb->out_fence) > + return -ENOMEM; > + > + dma_fence_init(vb->out_fence, &vb2_fence_ops, &q->out_fence_lock, > + q->out_fence_context, 1); > + if (!vb->out_fence) { > + put_unused_fd(vb->out_fence_fd); > + return -ENOMEM; > + } > + > + vb->sync_file = sync_file_create(vb->out_fence); > + if (!vb->sync_file) { > + put_unused_fd(vb->out_fence_fd); > + dma_fence_put(vb->out_fence); > + vb->out_fence = NULL; > + return -ENOMEM; > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(vb2_setup_out_fence); > + > /* > * vb2_start_streaming() - Attempt to start streaming. > * @q: videobuf2 queue > @@ -1482,6 +1552,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int > index, void *pb, > list_add_tail(&vb->queued_entry, &q->queued_list); > q->queued_count++; > q->waiting_for_buffers = false; > + q->queueing_started = 1; > vb->state = VB2_BUF_STATE_QUEUED; > vb->in_fence = in_fence; > > @@ -1545,6 +1616,11 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int > index, void *pb, > if (pb) > call_void_bufop(q, fill_user_buffer, vb, pb); > > + if (vb->out_fence) { > + fd_install(vb->out_fence_fd, vb->sync_file->file); > + vb->sync_file = NULL; > + } > + > dprintk(2, "qbuf of buffer %d succeeded\n", vb->index); > return 0; > > @@ -1552,6 +1628,16 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int > index, void *pb, > spin_unlock_irqrestore(&vb->fence_cb_lock, flags); > > err: > + if (vb->sync_file) { > + put_unused_fd(vb->out_fence_fd); > + vb->out_fence_fd = -1; > + > + dma_fence_put(vb->out_fence); > + > + fput(vb->sync_file->file); > + vb->sync_file = NULL; > + } > + > /* Fill buffer information for the userspace */ > if (pb) > call_void_bufop(q, fill_user_buffer, vb, pb); > @@ -1804,6 +1890,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q) > q->start_streaming_called = 0; > q->queued_count = 0; > q->error = 0; > + q->queueing_started = 0; > > list_for_each_entry(vb, &q->queued_list, queued_entry) { > spin_lock_irqsave(&vb->fence_cb_lock, flags); > @@ -2156,6 +2243,7 @@ int vb2_core_queue_init(struct vb2_queue *q) > spin_lock_init(&q->done_lock); > mutex_init(&q->mmap_lock); > init_waitqueue_head(&q->done_wq); > + spin_lock_init(&q->out_fence_lock); > > q->memory = VB2_MEMORY_UNKNOWN; > > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c > b/drivers/media/common/videobuf2/videobuf2-v4l2.c > index 1df5dd01c0cd..ab5b2b71d784 100644 > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c > @@ -217,7 +217,12 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, > void *pb) > b->sequence = vbuf->sequence; > b->reserved = 0; > > - b->fence_fd = 0; > + if (b->flags & V4L2_BUF_FLAG_OUT_FENCE) { > + b->fence_fd = vb->out_fence_fd; > + } else { > + b->fence_fd = 0; > + } > + > if (vb->in_fence) > b->flags |= V4L2_BUF_FLAG_IN_FENCE; > else > @@ -496,6 +501,10 @@ int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer > *b) > ret = __verify_planes_array(vb, b); > if (!ret) > vb2_core_querybuf(q, b->index, b); > + > + /* Do not return the out-fence fd on querybuf */ > + if (vb->out_fence) > + b->fence_fd = -1; We aren't returning the fence_fd but as per the uapi documentation we should. Which should we correct? Also, any reason we don't recycle the out fence? IOW, each time we queue a buffer, a new out fence is created and returned to user, and has to be closed. Thanks! -- Ezequiel GarcĂa, VanguardiaSur www.vanguardiasur.com.ar