[media] media: vb2: Share code between vb2_prepare_buf and vb2_qbuf
The two operations are very similar, refactor most of the code in a helper function. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
This commit is contained in:
Laurent Pinchart
Mauro Carvalho Chehab
parent
a517cca6b2
commit
012043b834
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@ -1231,6 +1231,101 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
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return ret;
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}
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static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
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const char *opname,
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int (*handler)(struct vb2_queue *,
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struct v4l2_buffer *,
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struct vb2_buffer *))
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{
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struct rw_semaphore *mmap_sem = NULL;
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struct vb2_buffer *vb;
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int ret;
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/*
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* In case of user pointer buffers vb2 allocators need to get direct
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* access to userspace pages. This requires getting the mmap semaphore
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* for read access in the current process structure. The same semaphore
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* is taken before calling mmap operation, while both qbuf/prepare_buf
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* and mmap are called by the driver or v4l2 core with the driver's lock
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* held. To avoid an AB-BA deadlock (mmap_sem then driver's lock in mmap
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* and driver's lock then mmap_sem in qbuf/prepare_buf) the videobuf2
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* core releases the driver's lock, takes mmap_sem and then takes the
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* driver's lock again.
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*
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* To avoid racing with other vb2 calls, which might be called after
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* releasing the driver's lock, this operation is performed at the
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* beginning of qbuf/prepare_buf processing. This way the queue status
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* is consistent after getting the driver's lock back.
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*/
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if (q->memory == V4L2_MEMORY_USERPTR) {
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mmap_sem = ¤t->mm->mmap_sem;
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call_qop(q, wait_prepare, q);
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down_read(mmap_sem);
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call_qop(q, wait_finish, q);
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}
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if (q->fileio) {
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dprintk(1, "%s(): file io in progress\n", opname);
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ret = -EBUSY;
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goto unlock;
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}
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if (b->type != q->type) {
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dprintk(1, "%s(): invalid buffer type\n", opname);
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ret = -EINVAL;
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goto unlock;
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}
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if (b->index >= q->num_buffers) {
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dprintk(1, "%s(): buffer index out of range\n", opname);
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ret = -EINVAL;
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goto unlock;
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}
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vb = q->bufs[b->index];
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if (NULL == vb) {
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/* Should never happen */
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dprintk(1, "%s(): buffer is NULL\n", opname);
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ret = -EINVAL;
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goto unlock;
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}
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if (b->memory != q->memory) {
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dprintk(1, "%s(): invalid memory type\n", opname);
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ret = -EINVAL;
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goto unlock;
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}
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ret = __verify_planes_array(vb, b);
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if (ret)
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goto unlock;
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ret = handler(q, b, vb);
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if (ret)
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goto unlock;
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/* Fill buffer information for the userspace */
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__fill_v4l2_buffer(vb, b);
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dprintk(1, "%s() of buffer %d succeeded\n", opname, vb->v4l2_buf.index);
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unlock:
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if (mmap_sem)
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up_read(mmap_sem);
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return ret;
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}
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static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
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struct vb2_buffer *vb)
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{
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if (vb->state != VB2_BUF_STATE_DEQUEUED) {
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dprintk(1, "%s(): invalid buffer state %d\n", __func__,
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vb->state);
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return -EINVAL;
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}
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return __buf_prepare(vb, b);
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}
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/**
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* vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
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* @q: videobuf2 queue
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@ -1248,87 +1343,44 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
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*/
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int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
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{
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struct rw_semaphore *mmap_sem = NULL;
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struct vb2_buffer *vb;
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int ret;
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/*
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* In case of user pointer buffers vb2 allocator needs to get direct
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* access to userspace pages. This requires getting read access on
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* mmap semaphore in the current process structure. The same
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* semaphore is taken before calling mmap operation, while both mmap
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* and prepare_buf are called by the driver or v4l2 core with driver's
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* lock held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in
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* mmap and driver's lock then mmap_sem in prepare_buf) the videobuf2
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* core release driver's lock, takes mmap_sem and then takes again
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* driver's lock.
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*
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* To avoid race with other vb2 calls, which might be called after
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* releasing driver's lock, this operation is performed at the
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* beggining of prepare_buf processing. This way the queue status is
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* consistent after getting driver's lock back.
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*/
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if (q->memory == V4L2_MEMORY_USERPTR) {
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mmap_sem = ¤t->mm->mmap_sem;
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call_qop(q, wait_prepare, q);
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down_read(mmap_sem);
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call_qop(q, wait_finish, q);
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}
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if (q->fileio) {
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dprintk(1, "%s(): file io in progress\n", __func__);
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ret = -EBUSY;
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goto unlock;
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}
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if (b->type != q->type) {
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dprintk(1, "%s(): invalid buffer type\n", __func__);
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ret = -EINVAL;
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goto unlock;
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}
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if (b->index >= q->num_buffers) {
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dprintk(1, "%s(): buffer index out of range\n", __func__);
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ret = -EINVAL;
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goto unlock;
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}
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vb = q->bufs[b->index];
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if (NULL == vb) {
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/* Should never happen */
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dprintk(1, "%s(): buffer is NULL\n", __func__);
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ret = -EINVAL;
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goto unlock;
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}
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if (b->memory != q->memory) {
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dprintk(1, "%s(): invalid memory type\n", __func__);
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ret = -EINVAL;
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goto unlock;
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}
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if (vb->state != VB2_BUF_STATE_DEQUEUED) {
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dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state);
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ret = -EINVAL;
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goto unlock;
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}
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ret = __verify_planes_array(vb, b);
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if (ret < 0)
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goto unlock;
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ret = __buf_prepare(vb, b);
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if (ret < 0)
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goto unlock;
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__fill_v4l2_buffer(vb, b);
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unlock:
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if (mmap_sem)
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up_read(mmap_sem);
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return ret;
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return vb2_queue_or_prepare_buf(q, b, "prepare_buf", __vb2_prepare_buf);
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}
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EXPORT_SYMBOL_GPL(vb2_prepare_buf);
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static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b,
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struct vb2_buffer *vb)
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{
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int ret;
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switch (vb->state) {
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case VB2_BUF_STATE_DEQUEUED:
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ret = __buf_prepare(vb, b);
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if (ret)
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return ret;
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case VB2_BUF_STATE_PREPARED:
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break;
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default:
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dprintk(1, "qbuf: buffer already in use\n");
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return -EINVAL;
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}
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/*
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* Add to the queued buffers list, a buffer will stay on it until
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* dequeued in dqbuf.
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*/
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list_add_tail(&vb->queued_entry, &q->queued_list);
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vb->state = VB2_BUF_STATE_QUEUED;
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/*
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* If already streaming, give the buffer to driver for processing.
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* If not, the buffer will be given to driver on next streamon.
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*/
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if (q->streaming)
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__enqueue_in_driver(vb);
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return 0;
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}
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/**
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* vb2_qbuf() - Queue a buffer from userspace
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* @q: videobuf2 queue
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@ -1348,103 +1400,7 @@ EXPORT_SYMBOL_GPL(vb2_prepare_buf);
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*/
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int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
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{
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struct rw_semaphore *mmap_sem = NULL;
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struct vb2_buffer *vb;
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int ret = 0;
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/*
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* In case of user pointer buffers vb2 allocator needs to get direct
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* access to userspace pages. This requires getting read access on
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* mmap semaphore in the current process structure. The same
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* semaphore is taken before calling mmap operation, while both mmap
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* and qbuf are called by the driver or v4l2 core with driver's lock
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* held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in
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* mmap and driver's lock then mmap_sem in qbuf) the videobuf2 core
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* release driver's lock, takes mmap_sem and then takes again driver's
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* lock.
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*
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* To avoid race with other vb2 calls, which might be called after
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* releasing driver's lock, this operation is performed at the
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* beggining of qbuf processing. This way the queue status is
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* consistent after getting driver's lock back.
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*/
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if (q->memory == V4L2_MEMORY_USERPTR) {
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mmap_sem = ¤t->mm->mmap_sem;
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call_qop(q, wait_prepare, q);
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down_read(mmap_sem);
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call_qop(q, wait_finish, q);
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}
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if (q->fileio) {
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dprintk(1, "qbuf: file io in progress\n");
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ret = -EBUSY;
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goto unlock;
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}
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if (b->type != q->type) {
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dprintk(1, "qbuf: invalid buffer type\n");
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ret = -EINVAL;
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goto unlock;
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}
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if (b->index >= q->num_buffers) {
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dprintk(1, "qbuf: buffer index out of range\n");
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ret = -EINVAL;
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goto unlock;
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}
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vb = q->bufs[b->index];
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if (NULL == vb) {
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/* Should never happen */
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dprintk(1, "qbuf: buffer is NULL\n");
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ret = -EINVAL;
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goto unlock;
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}
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if (b->memory != q->memory) {
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dprintk(1, "qbuf: invalid memory type\n");
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ret = -EINVAL;
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goto unlock;
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}
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ret = __verify_planes_array(vb, b);
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if (ret)
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goto unlock;
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switch (vb->state) {
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case VB2_BUF_STATE_DEQUEUED:
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ret = __buf_prepare(vb, b);
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if (ret)
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goto unlock;
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case VB2_BUF_STATE_PREPARED:
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break;
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default:
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dprintk(1, "qbuf: buffer already in use\n");
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ret = -EINVAL;
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goto unlock;
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}
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/*
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* Add to the queued buffers list, a buffer will stay on it until
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* dequeued in dqbuf.
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*/
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list_add_tail(&vb->queued_entry, &q->queued_list);
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vb->state = VB2_BUF_STATE_QUEUED;
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/*
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* If already streaming, give the buffer to driver for processing.
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* If not, the buffer will be given to driver on next streamon.
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*/
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if (q->streaming)
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__enqueue_in_driver(vb);
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/* Fill buffer information for the userspace */
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__fill_v4l2_buffer(vb, b);
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dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
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unlock:
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if (mmap_sem)
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up_read(mmap_sem);
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return ret;
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return vb2_queue_or_prepare_buf(q, b, "qbuf", __vb2_qbuf);
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}
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EXPORT_SYMBOL_GPL(vb2_qbuf);
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