FC4: DVD DMA on Dell Notebook?

[Schlueri]

On a Dell Inspiron 9300 i'm unable to play dvd, because the dma is not
enabled. I think i'll run into problems if i try to burn cd/dvd.

Try to set dma with hdparm gives me the following error:

# hdparm -d 1 /dev/hdc

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


I found this:
http://forums.fedoraforum.org/showthread.php?p=279310#post279310

Is this the only way to enable dvd dma or can i just set an kernel
option on boot?

Thank you.
Dirk