On Fri, Jul 30, 2010 at 11:21:42AM -0700, Eric W. Biederman wrote: > David Woodhouse <dwmw2 at infradead.org> writes: > > > On Thu, 2010-07-29 at 21:41 -0700, Eric W. Biederman wrote: > >> There isn't a bus master shut off at the core level. > > > > Effectively, there is if you have an IOMMU. > > Depends on the IOMMU. There are several dinky IOMMUs that when you > shut them off DMA simply goes around them, and is not stopped. I think last time we were discussing this for AMD IOMMU where if you disable IOMMU, it just kind of become pass through with 1:1 mapping of addresses. Vivek
