int drm_addbufs_agp (struct inode * inode, struct file * filp, unsigned int cmd, unsigned long arg);
\param inode device inode. \param filp file pointer. \param cmd command. \param arg pointer to a drm_buf_desc_t request. \return zero on success or a negative number on failure.
After some sanity checks creates a drm_buf structure for each buffer and reallocates the buffer list of the same size order to accommodate the new buffers.