I've been triying to watch DVD movies in my Dell laptop (Linux Fedora C6). Xine was the solution BUT... when I ran xine-check, because movies run with a little flick, return:

[ hint ] DMA is disabled for your DVD interface.
This will probably result in a serious performance hit when
playing DVDs. You can issue the command
hdparm -d1 /dev/hdc
as root to enable DMA. It would be wise to add this command to
some script that is executed executed at boot time.
Note that you probably have to set the DMA mode for your drive as well.
Most DVD-ROMs work fine with multiword DMA mode 2. You can use
hdparm -d1 -X34 /dev/hdc
(as root again) to set this mode. Maybe UDMA2 will give you even better
performance, but it only works well with some controllers. You'll
probably need UDMA capable IDE cables for this mode. If you want
to try: make backups of your important data and type (as root again)
sync
hdparm -d1 -X66 /dev/hdc
If your System still works fine after this, you probably want to keep
these settings (add them to some boot script).
If your system hangs or behaves very strangely after a few minutes, you
should reboot immediately and never use this setting again on this
machine. Good luck ;-)


So I did hdparm -d1 /dev/hdc
And returns

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

I try to enable DMA in BIOS, did'n work.
I update and custom the kernel (from 2.6.18-1 to 2.6.18-2) and yes I enabled DMA for Intel chipset, but I'm still having the same problem.

PD: I'm really really new Linux user so be nice.(I'm still learning)

OK, you did the commands as root, correct? Here are a few suggestions. No guarantees, but maybe it will get you somewhere and be sure /hdc is the correct device.

First, try hdparm -I /dev/hdc
This will return all available info the drive has on itself. If it is DMA/UDMA capable, it will list the possible modes. One mode may have a * beside it, indicating that mode is in effect.

Next, try hdparm -c /dev/hdc
This will tell you if the drive is using 16 or 32 bit IO. The drive may need to be using 32 bit IO in order to provide DMA access. If it is 16 bit, then do:
hdparm -c 1 /dev/hdc
to set the device to 32 bit IO.
If this fails, verify in your BIOS if/whether the IDE bus can be set to 32 bit IO for any devices. Mine does have the option, many do, but some may not.
If 32 bit mode does work, try setting the checking/setting DMA again: hdparm -d 1 /dev/hdc

If none of this has worked, go into the BIOS and disable FAST-BOOT if it is there, and also, if you can, change the POST/BIOS option to BIOS (usually the default) so you get the text-screen with all the BIOS info when you boot, instead of the Graphic Dell-Screen.
Now, when you reboot,the computer should boot slower, and when the BIOS info comes on the screen (it may be very quick, so look carefully) see if there is a line which says something like : Warning: No 80-conductor cable connected on IDE 2" Or something very similar to that. The message may be accompanied by a 'beep' from the computer.
The reason for this test is this: Some IDE drives and CD-devices will not go into or above DMA 2 or greater when there is an 80 conductor IDE cable being used. If the BIOS detects an 80 conductor cable, it may not let the device use DMA.
Finally, post the results of all this. If you do have an 80 conductor cable, you may need to switch it with the standard 40 conductor variety. There is also an option in the linux kernel called "Disable Word93 Validation" which attempts to circumvent this issue, but it is not guaranteed to work.
Best of luck.
Remember, none of this may help your DMA problem, but none of it is potentially harmful either, and you can learn a little bit about your drive
Please let us know how you make out.

I did all:
-same error in DMA
-Disable fast-boot and I could`n see any menssage because my Laptop do not have POST/BIOS so I only watch DELL screen, but yes it started very slow
-I did enable DVD form 16 to 32 bit :-) at least
-hdparm -I /dev/hdc return this:
/dev/hdc:

ATAPI CD-ROM, with removable media
Model Number: HL-DT-STCD-RW/DVD-ROM GCC-4244N
Serial Number:
Firmware Revision: B101
Standards:
Likely used CD-ROM ATAPI-1
Configuration:
DRQ response: 50us.
Packet size: 12 bytes
Capabilities:
LBA, IORDY(can be disabled)
DMA: sdma0 sdma1 sdma2 mdma0 mdma1 mdma2 udma0 udma1 *udma2
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns
HW reset results:
CBLID- below Vih
Device num = 0 determined by CSEL

Any other idea,

Thanks a lot. Im still trying :-)

Not really sure what more I can suggest. The info above DOES say *udma2, however it is strange that it reports 'operation not permitted' and xine says DMA is off.
I have read a few links from Google that suggest ACPI can cause problems for that drive, but I haven't read anything conclusive yet.

One thing I DID discover, is that there is a newer Firmware available for the drive. Do you have Windows installed anywhere in that computer? This one I am looking at is for Windows, however I have installed Firmware in my CD drive just by booting into MS-DOS. Your drive is version B101. The new version is B103. It might fix the issue. Here is the download page:
http://www.opendrivers.com/driver/23...-download.html

No I have only Linux in my Laptop but I changed disk drive from other similar laptop and did the job.
I updated from B101 to B103. Also I took one step forward and updated BIOS ver from A03 to A06 but is still not working.

Sheesh.. Well, I really have no idea what else to suggest. I just don't know.
I guess do some intensive Gooogling I did see a fair number of links, threads and webpages with content about that type if drive.
Good luck, and do let us know if you get it fixed.
Also, maybe you could see if the device is listed in the HCL, and if not, perhaps add it, so others will either know of the issue existing, or be able to offer help if they have the same device.

Thanks a lot for your time. I will work again with my kernel becase it seems to be the solution acording to google.

I'm still trying.

I will let you know :-)

I did my homework, and the problem is about SATA/SCSI in Linux, I do not understand yet(I m working on it).

Ok, I found a solution to my real problem xine "jumpy" and is this for those folks with the same problem.

Just run: hdparm -c1 -a1 -u1 /dev/"your device"

I m watching movies

But I m still trying DMA thing

Always trying

Thanks GrapefruTgirl you show me the path

OK I'm back, just in case some one have the same DMA problem, and yes is because Dell D610 use a SCSI. I move OS to Fedora 7 and the problem disappear. The device is an /dev/scd0 not hdc.

Thanks