> does anything think that it's a mistake to default dma on? I have a lot of old kit around and can't for the hell of me figure out which drives do need and which ones don't want DMA, occasionally losing if nothing else a lot of time and effort in repairing a bad assumption. Having a kernel instruction can only be very useful; setting an arbitrary initial condition isn't really that helpful either way.
The default, of course, would have to be ON if most hardware is to be taken into account. I'm not sure, given that old drives had unlimited lifespans and new drives only last a year or so, who wins that competition :-) Probably the motherboards: the old ones just can't compete. ++L