linux-4.4.1/vb2_core_expbuf() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-4.4.1/vb2_core_expbuf() へ行く。
  • 1 (2016-02-24 (水) 17:45:02)

---

参照元†

• linux-4.4.1/vb2_expbuf()

説明†

• パス: linux-4.4.1/drivers/media/v4l2-core/videobuf2-core.c

• FIXME: これは何？
  • 説明

引数†

• struct vb2_queue *q
  • linux-4.4.1/vb2_queue
• int *fd
• unsigned int type
• unsigned int index
• unsigned int plane
• unsigned int flags

返り値†

• int

参考†

実装†

/**
 * vb2_core_expbuf() - Export a buffer as a file descriptor
 * @q:          videobuf2 queue
 * @fd:         file descriptor associated with DMABUF (set by driver) *
 * @type:       buffer type
 * @index:      id number of the buffer
 * @plane:      index of the plane to be exported, 0 for single plane queues
 * @flags:      flags for newly created file, currently only O_CLOEXEC is
 *              supported, refer to manual of open syscall for more details
 *
 * The return values from this function are intended to be directly returned
 * from vidioc_expbuf handler in driver.
 */
int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
                unsigned int index, unsigned int plane, unsigned int flags)
{
        struct vb2_buffer *vb = NULL;
        struct vb2_plane *vb_plane;
        int ret;
        struct dma_buf *dbuf;

• • linux-4.4.1/vb2_buffer
  • linux-4.4.1/vb2_plane
  • linux-4.4.1/dma_buf

        if (q->memory != VB2_MEMORY_MMAP) {
                dprintk(1, "queue is not currently set up for mmap\n");
                return -EINVAL;
        }

• • linux-4.4.1/dprintk()

        if (!q->mem_ops->get_dmabuf) {
                dprintk(1, "queue does not support DMA buffer exporting\n");
                return -EINVAL;
        }

• q->mem_ops は 型
  • [[linux-4.4.1/]]

        if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
                dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
                return -EINVAL;
        }

        if (type != q->type) {
                dprintk(1, "invalid buffer type\n");
                return -EINVAL;
        }

        if (index >= q->num_buffers) {
                dprintk(1, "buffer index out of range\n");
                return -EINVAL;
        }

        vb = q->bufs[index];

• q->bufs は 型
  • [[linux-4.4.1/]]

        if (plane >= vb->num_planes) {
                dprintk(1, "buffer plane out of range\n");
                return -EINVAL;
        }

        if (vb2_fileio_is_active(q)) {
                dprintk(1, "expbuf: file io in progress\n");
                return -EBUSY;
        }

• • linux-4.4.1/vb2_fileio_is_active()

        vb_plane = &vb->planes[plane];

• vb->planes は 型
  • [[linux-4.4.1/]]

       dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
                               flags & O_ACCMODE);

• • linux-4.4.1/call_ptr_memop()

       if (IS_ERR_OR_NULL(dbuf)) {
               dprintk(1, "failed to export buffer %d, plane %d\n",
                       index, plane);
               return -EINVAL;
       }

• • linux-4.4.1/IS_ERR_OR_NULL()

       ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
       if (ret < 0) {
               dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
                       index, plane, ret);
               dma_buf_put(dbuf);
               return ret;
       }

• • linux-4.4.1/dma_buf_fd()
  • linux-4.4.1/dma_buf_put()

       dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
               index, plane, ret);
       *fd = ret;

       return 0;

} EXPORT_SYMBOL_GPL(vb2_core_expbuf);

• • linux-4.4.1/EXPORT_SYMBOL_GPL()

コメント†