CF cards

Reab
2006-11-27
2013-04-27
  • Reab
    Reab
    2006-11-27

    I noticed that when setting the PIO mode, it is not reflected in the overview. The MDMA* is removed however. Is it a 'feature' or is it simply not possible to get the curent active mode when PIO is selected?

    hdparm -i /dev/hda
    ....
    PIO modes:  pio0 pio1 pio2 pio3 pio4
    DMA modes:  mdma0 mdma1 mdma2*
    AdvancedPM=no

    * signifies the current active mode

    hdparm -p4 /dev/hda
    hdparm -i /dev/hda
    ....
    PIO modes:  pio0 pio1 pio2 pio3 pio4
    DMA modes:  mdma0 mdma1 mdma2
    AdvancedPM=no

    * signifies the current active mode

    I was using CF card to boot from and MDMA2 (default setting) eventually caused 'lost interrupt' errors. Choosing PIO4 solved it.

    Another question...
    If MDMA2 is chosen as a default startup setting from the CF card, but the DMA bit is 0 (=DMA diabled, [hdparm -d0 /dev/hda])...Does it effectively mean that DMA is in fact enabled (due to MDMA2), thus causing  'lost interrupts'?

    Thanks
    /Reab