I compiled my own kernel, with apt-get install linux-source-2.6.17 and some other commands, while applying the patch. Looks like the -6 kernel in ubuntu edgy didn't include the patch, and looks like the patch fixes my problem completely (hdparm -tT goes from 3 to 25 MB/s).
Are you sure the patch was included in the ubuntu kernel tree? -- DMA not enabled for IDE disks https://launchpad.net/bugs/55929 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
