I have Acer Travelmate 3250 laptop (Core Duo).

Activating DMA on my harddrive seems to be impossible. The IDE controller is:

I also checked, I checked the option "Intel PIIXn chipsets support" in the kernel configuration "ATA/ATAPI/MFM/RLL support"

and also checked "Intel ESB, ICH, PIIX3 PIIX4 PATA/SATA SUPPORT" and "AHCI SATA SUPPORT" under
"Serial ATA(prod) and Parallel ATA (experimental) drivers" and even I checked "Generic ATA support"

When I run hdparm as root, it shows me this :

# hdparm -d1 /dev/sda
/dev/sda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Invalid argument

Is there anything else I must do to get working?

Please Help me..

Isn't DMA an IDE thing? You have SATA, I see.

So you would say, no DMA for SATA is normal ?

Generally recent kernels activate DMA for IDE disks automatically whenever it's possible. If it's turned off then activating it manually mostly won't work.
IDE disks have built-in controllers, thus the need for DMA. The thing on the motherboard called "IDE controller" merely provides IDE interface.
SCSI controllers are real controllers, consequently there is no such thing as DMA for SCSI disks.
I think SATA works like SCSI.

So, my effort to activating the DMA is useless?

and then is my "Timing buffered disk reads" normal?

# hdparm -tT /dev/hda
/dev/hda:
Timing cached reads: 4564 MB in 2.00 seconds = 2282.73 MB/sec
Timing buffered disk reads: 4 MB in 3.07 seconds = 1.30 MB/sec

Um...how about my /dev/cdrom ? I also can't activate it. My K3b warned me that DMA is not activated.

If you said that, should I ignore that warning?

Disk read 1.3 MB/s is not normal indeed. I think your kernel is using generic IDE driver for your controller. I'm not familiar with this h/w, is your HDD SATA or not? SATA devices should show up as sdx if kernel is configured properly.

I have a SATA hard drive, and it does not have a DMA setting. If you're using PATA drives, this page may be of some use. Further down the thread in that link there is a full patch, although given that it was signed off in September last year, it should have made it into recent kernels.

nope my hard disk is not SATA, /dev/hda is absolutely correct.

I have never patch kernel before, could you tell me how to apply that patch please..

The full patch, I guess in this link, right? ( http://www.spinics.net/lists/linux-ide/msg04810.html )

And also, the path of ata_piix.c (in that link is linux-2.6.17-new/drivers/scsi/ata_piix.c ) file is different in kernel 2.6.21.1. In the kernel 2.6.21.1 is in "drivers/ata". Then can this patch apply to this new kernel?

thx

That's the right page, indeed. I've never tried patching a kernel myself, so I think it would be best if someone more knowledgeable could answer your question about that. At a guess, I'd say it's probably best not to apply the patch to a different kernel version though. As I mentioned earlier, given that that patch was released some months ago, I'd be surprised if it hadn't already made it into the kernel for 2.6.21. Since it's a fairly short patch, it might be worth opening up the unpatched 2.6.21 source file and checking the code, and applying the patch manually if necessary. At least you'll know exactly what's going on then, even if it takes a few extra minutes. Of course, backing up the source file in question before modification would probably be a good idea!

Thank you very much. I understood what you mean. Very appreciate your reply and help