ouranos ui # hdparm -d 1 /dev/cdrom 

/dev/cdrom:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)
ouranos ui # hdparm -d /dev/cdrom 

/dev/cdrom:
 using_dma    =  0 (off)