On Sun, 29 Jun 2003 00:01, Gareth Williams wrote: > I recently upgraded my kernel from 2.4.10 to 2.4.21, compiled from source > with basically the same .config as 2.4.10 had. It all works fine, except > now when I try the above hdparm line (as root) I get: > HDIO_SET_DMA failed: Operation not permitted > > If I boot the old kernel it all works fine. > If anyone has any clue why this might be, I would love to know.
Is DMA already set? I have a feeling (but no proof) that new kernels automagically put all harddisks into DMA mode (when it can), whereas older kernels didn't. I know that new kernels (probably 2.6 or 3.0 or whatever) will have a different way of interacting with/controling IO devices. Moving away from ioctl system calls to /proc entries. SO.... you may need to update your hdparm (probably not a bad idea anyway, after a kernel build). Hope this helps. Later Lee
