Trying to turn off DMA on my Linux machine returns:
HDIO_GET_DMA failed: Inappropriate ioctl for device
I remember that this used to work to turn DMA on or off. I also tried using the kernel parameter
libata.dma=0 but it had no effect! The ATA driver and DMA seem to work well however. So I just wonder weather I should worry about this or it is just not supported anymore.
The distro is Ubuntu 12 and the kernel is 3.5.0-54-generic. The chipset is
00:1f.2 SATA controller: Intel Corporation 7 Series/C210 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04)