RH9 enabling DMA for DVD/CD/CDRW combo
 

Hi there,

I was wondering if someone can help me with my problem. For some unknown reason I can't enable any DMA for my DVD/CD/CD RW combo which seems to be essential for smooth playing of my DVDs. I'm running on RH9. I've tried this

[root@localhost root]# hdparm -c3 -d1 -X sdma1 -u1 /dev/hdc

and this is what I got from it:

/dev/hdc:
setting 32-bit IO_support flag to 3
setting unmaskirq to 1 (on)
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
setting xfermode to 17 (singleword DMA mode1)
IO_support = 3 (32-bit w/sync)
unmaskirq = 1 (on)
using_dma = 0 (off)

Everything is all right except for the last line in that message. I put this line into /etc/modules.conf

options ide-cd dma=1

but when I restarted I got this in /var/log/messages

...
...
Oct 3 20:41:43 localhost kernel: Kernel command line: ro root=LABEL=/ hdc=ide
Oct 3 20:41:43 localhost kernel: ide_setup: hdc=ide -- BAD OPTION
...
...

In order to disable SCSI emulation of my IDE combo device I've deleted hdc=ide-scsi in my grub.conf so now it looks like this

...
kernel /vmlinuz-2.4.20-8 ro root=LABEL=/ hdc=ide
....

If I run this
[root@localhost root]# hdparm -d1 /dev/hdc

I got this

/dev/hdc:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)
[root@localhost root]#

Can anyone help me to sort this out please?

cheers
rf