IDE settings (WAS: [MPlayer-users] DVD playback)

[Frank Boehme]

Sven Hartge wrote:

> Prepare for data loss. All DMA-Modes below UDMA66 _do not use error
> correction_, so if you *force* UDMA33 for example, even if the kernel
> insists switching it off, you may introduce errors into the date read or
> written.

Hm. My idea was to do this (forcing dma) only for playing dvds, because
it worked well when I did it manually. That is, the movie becomes a
little bit more jerkey, I switch to a console and check the IDE
settings, they are back to default because of a recent dma timeout, I
set them back to dma and unmasking other IRQs and the movie continues to
play well again.

> So be careful, the kernel has a reason to switch DMA off.

Ok. I also understand that dma has not as much influence on throughput
as unmasking other IRQs.

Frank