Updating linux kernal
Other reasons can show up in the event log, so check this first and see if you can find repeated Atapi errors recorded. You can use the procedures described on this page, but your computer will probably fall back to PIO mode again and again, until you solve the underlying problem, which may be located inside the device, on the motherboard, or in the IDE data cable and its connectors.A dramatic example was reported on 2006-12-29 by David Hähningen: If you (half asleep in the dark and with considerable force) try to put the ATA plug on the hard disk the wrong way around, the gap called "KEYPIN" (pin 20 on the plug) pushes pin 21 of the hard disk socket and bends it aside.
If you try, without using special software, to copy such a DVD (which doesn't work), then this can already trigger the problem.
If you use the program again after a short while, it may again report that it has reset the channels.
This is normal behavior and not a sign of any problem. (Peter Frank reported successful application on Windows 2000 with Service Pack 4.) DMA is an abbreviation for Direct Memory Access, an access method for external devices where the data transfer is not done by the central processor, but by a small special processor called DMA controller.
It uses a procedure called cycle stealing, where the central processor memory access cycles are delayed for very short times to intersperse DMA controller memory access cycles.
Some newer, faster DMA modes are called UDMA (Ultra DMA).