please help me !about the idedisk driver!

we have a embeded system .The achitecture is MPC8245+intel82371southbrige+ide hard disk.Now the question is as follow:The ide hard disk can work well int the pio mode,but
in DMA mode it can not work ! The debuge information printed is "DMA time out!" when the driver start the DMA transe process,The hard disk did not generate the interruption.The hard disk had tested to support DMA!