dma bekapcsolása cdrom-okra

A k3b indításkor panaszkodott, hogy a cd-meghajtók esetében nincs bekapcsolva a dma.
Ennek örömére megpróbáltam bekapcsolni a közvetlen memóriahozzáférést a két meghajtóra.
A következő hibaüzenetet kaptam:

root@nostromo:~# hdparm -d 1 /dev/hdb

/dev/hdb:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma     =  0 (off)
root@nostromo:~# hdparm -d 1 /dev/hdc

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

A meghajtók a kövezkezők:

root@nostromo:~# hdparm -iI /dev/hdb

/dev/hdb:

 Model=HL-DT-ST DVDRAM GSA-4082B, FwRev=A201, SerialNo=K2744DA2025
 Config={ Fixed Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic }
 RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
 BuffType=unknown, BuffSize=0kB, MaxMultSect=0
 (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio3 pio4
 DMA modes:  mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 *udma2
 AdvancedPM=no
 Drive conforms to: Unspecified:  ATA/ATAPI-2,3,4,5

 * signifies the current active mode


ATAPI CD-ROM, with removable media
        Model Number:       HL-DT-ST DVDRAM GSA-4082B
        Serial Number:      K2744DA2025
        Firmware Revision:  A201
Standards:
        Likely used CD-ROM ATAPI-1
Configuration:
        DRQ response: 50us.
        Packet size: 12 bytes
Capabilities:
        LBA, IORDY(can be disabled)
        DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2
             Cycle time: min=120ns recommended=120ns
        PIO: pio0 pio1 pio2 pio3 pio4
             Cycle time: no flow control=120ns  IORDY flow control=120ns
HW reset results:
        CBLID- above Vih
        Device num = 1
root@nostromo:~# hdparm -iI /dev/hdc

/dev/hdc:

 Model=ASUS CRW-5232AS, FwRev=1.0, SerialNo=
 Config={ Fixed Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic }
 RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
 BuffType=unknown, BuffSize=0kB, MaxMultSect=0
 (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
 IORDY=yes, tPIO={min:227,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4
 DMA modes:  mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 *udma2
 AdvancedPM=no

 * signifies the current active mode


ATAPI CD-ROM, with removable media
        Model Number:       ASUS    CRW-5232AS
        Serial Number:
        Firmware Revision:  1.0
Standards:
        Likely used CD-ROM ATAPI-1
Configuration:
        DRQ response: 50us.
        Packet size: 12 bytes
Capabilities:
        LBA, IORDY(cannot be disabled)
        DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2
             Cycle time: min=120ns recommended=120ns
        PIO: pio0 pio1 pio2 pio3 pio4
             Cycle time: no flow control=227ns  IORDY flow control=120ns

Az ide vezérlő:

00:1f.1 IDE interface: Intel Corporation 82801EB/ER (ICH5/ICH5R) IDE Controller (rev 02)

Ami vicces az az, hogy a biosban bekapcsoltam a 32 bites átviteli módot a cdkre, és a hdparm is ezt mutatja, ennek ellenére mégis panaszkodik a k3b...