On Apr 27, 2007, at 5:48 AM, Jachym Holecek wrote:

> IIRC the idea behind volatile removal in USB code was that _sync()
> implies memory barrier -- which is not the case b/c any bus_dma(9)
> operation is explicitely allowed to be implemented as a macro (and
> actually can evaluate to "(void)0" on some arches), ie. not function
> call with its implications.

This should probably be changed in the bus_dma specification.

-- thorpej