DMA under RedHat 7.3

sp0t · 08-11-2002, 01:42 PM

Hi,

I have some trouble activating DMA for my DVD (/dev/hdc).

I had this in my rc.local:

/sbin/hdparm -c 3 -d 1 /dev/hdc

in order to activate I/O 32 bits support and DMA. Flag I/O is ok but not for the DMA:

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

Even if I am logged in root (!) and in the BIOS my DVD is in PIO Mode 4.

Thx for your help and exc for my english.

sp0t

PS: I use RedHat 7.3

Mara · 08-12-2002, 06:00 PM

For me it looks that your DVD does not accept DMA. It looks strange, I must say.
I'm not sure, but maybe it has something to do with having/not having something in the drive.

sp0t · 08-14-2002, 01:54 AM

Problem solved.

It was a kernel problem. I updated it and know I can activate the DMA access.

But thx for reading this topic

.

davewebb · 10-10-2002, 02:16 PM

What exactly did you do to update the kernel?

Newer kernel?
What version?
Specific flag?

Thanks,
Dave