linux-4.4.1/__vb2_queue_alloc() 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_queue_alloc() へ行く。
  • 1 (2016-02-08 (月) 18:27:34)
  • 2 (2016-02-08 (月) 18:27:47)

参照元†

• linux-4.4.1/vb2_core_reqbufs()

説明†

• パス: [[linux-4.4.1/]]

• FIXME: これは何？
  • 説明

引数†

• struct vb2_queue *q
  • linux-4.4.1/vb2_queue
• enum vb2_memory memory
  • linux-4.4.1/vb2_memory
• unsigned int num_buffers
• unsigned int num_planes

返り値†

• int

参考†

実装†

/**
 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 * video buffer memory for all buffers/planes on the queue and initializes the
 * queue
 *
 * Returns the number of buffers successfully allocated.
 */
static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
                             unsigned int num_buffers, unsigned int num_planes)
{
        unsigned int buffer;
        struct vb2_buffer *vb;
        int ret;

• • linux-4.4.1/vb2_buffer

        for (buffer = 0; buffer < num_buffers; ++buffer) {
                /* Allocate videobuf buffer structures */
                vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
                if (!vb) {
                        dprintk(1, "memory alloc for buffer struct failed\n");
                        break;
                }

• • linux-4.4.1/kzalloc()
  • linux-4.4.1/dprintk()

                vb->state = VB2_BUF_STATE_DEQUEUED;
                vb->vb2_queue = q;
                vb->num_planes = num_planes;
                vb->index = q->num_buffers + buffer;
                vb->type = q->type;
                vb->memory = memory;

                /* Allocate video buffer memory for the MMAP type */
                if (memory == VB2_MEMORY_MMAP) {
                        ret = __vb2_buf_mem_alloc(vb);
                        if (ret) {
                                dprintk(1, "failed allocating memory for "
                                                "buffer %d\n", buffer);
                                kfree(vb);
                                break;
                        }

• • linux-4.4.1/__vb2_buf_mem_alloc()
  • linux-4.4.1/kfree()

                        /*
                         * Call the driver-provided buffer initialization
                         * callback, if given. An error in initialization
                         * results in queue setup failure.
                         */
                        ret = call_vb_qop(vb, buf_init, vb);
                        if (ret) {
                                dprintk(1, "buffer %d %p initialization"
                                        " failed\n", buffer, vb);
                                __vb2_buf_mem_free(vb);
                                kfree(vb);
                                break;
                        }

• • vb->vb2_queue->ops->buf_init が呼ばれる。
    • vb->vb2_queue は struct vb2_queue * 型
    • linux-4.4.1/vb2_queue()
    • vb->vb2_queue->ops は const struct vb2_ops * 型
    • linux-4.4.1/vb2_ops()
  • linux-4.4.1/call_vb_qop()
  • linux-4.4.1/__vb2_buf_mem_free()

                }

                q->bufs[q->num_buffers + buffer] = vb;
        }

        __setup_lengths(q, buffer);
        if (memory == VB2_MEMORY_MMAP)
                __setup_offsets(q, buffer);

• • linux-4.4.1/__setup_lengths()
  • linux-4.4.1/__setup_offsets()

        dprintk(1, "allocated %d buffers, %d plane(s) each\n",
                        buffer, num_planes);

        return buffer;
}

コメント†