No DMA on a Dell Latitude D820 with >2.6.20

Hi,

I'm having problems with my disk on a Latitude D820 after upgrading kernel to any >2.6.20 No DMA support can be activated, giving me a very poor I/O performance.

I'm using ata_piix driver on a ICH7 system with no AHCI support AFAIK

I opened a thread[1] on gentoo-forums (the distro I use) with all the output i think can be interesting.

Hope you can help me guys. Thanks for all :)

[1] http://forums.gentoo.org/viewtopic-p-4731161.html

Mikel Olasagasti <[email protected]>

..

Actually, no. You are really using the IDE driver ("hda") for your disk on the 2.6.23 kernel.

You can fix this by just not including the IDE driver in your kernel build, and by fixing your /boot/grub/menu.lst file to use root=/dev/sda6 instead of root=/dev/hda6.

Plus whatever special soup gentoo might require.

Cheers