Promise 20267 in DMA mode?

[Iain <iain@myspinach.org>]

Hi,

How do I enable DMA for my Promise 20267 raid controller? I'm using kernel 
2.4.18 with relevant config details:

CONFIG_BLK_DEV_PDC202XX=y
CONFIG_PDC202XX_BURST=y
# CONFIG_PDC202XX_FORCE is not set
CONFIG_BLK_DEV_ATARAID_PDC=y

cat /proc/ide/pdc202xx gives:

                                PDC20267 Chipset.
------------------------------- General Status 
---------------------------------
Burst Mode                           : enabled
Host Mode                            : Normal
Bus Clocking                         : 66 External
IO pad select                        : 10 mA
Status Polling Period                : 0
Interrupt Check Status Polling Delay : 0
--------------- Primary Channel ---------------- Secondary Channel 
-------------
                enabled                          enabled
66 Clocking     disabled                         disabled
           Mode MASTER                      Mode MASTER
                FIFO Empty                       FIFO Empty
--------------- drive0 --------- drive1 -------- drive0 ---------- drive1 
------
DMA enabled:    no               no              no                no
DMA Mode:       UDMA 4           NOTSET          UDMA 4            NOTSET
PIO Mode:       PIO ?            NOTSET           PIO ?            NOTSET

If I try hdparm -d1 /dev/hde it gives:

/dev/hde:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

Please CC replies to me.

thanks, Iain.

-- 
PGP info: http://www.myspinach.org/~iain/pgpinfo.html