hdparm.conf

[ZIYAD A. M. AL-BATLY]

On Sun, 2005-07-24 at 20:04 +0300, ZIYAD A. M. AL-BATLY wrote:
> On Sun, 2005-07-24 at 12:15 +0100, david wrote: 
> > OK,
> > 
> > If that is the conf file for hdparm and all the lines in it are
> > commented out, then how come the hard drive has DMA enabled and the CD
> > drives don't? 
> > What I mean is, where else are the drives getting configurations from?
> > 
> > nux
> > 
> > 
> Your system's BIOS!  My system is like that.  Most (all?) BIOSes set DMA
> on for hard-drives but not all set it for CD-ROM/DVD devices.
> 
> Ziyad.
> 
Also, I just found¹ that Ubuntu by default compiles their Kernels with
the "CONFIG_IDEDMA_ONLYDISK" option set, which in effect disable the DMA
for anything other than HDD.

Ziyad.

Footnotes:
     1. Thanks to Wenzhuo Zhang for mentioning that on another message
        in this same thread.  I replied just to fix my mistake (I
        thought system BIOS is the only thing responsible for that).