David Woodhouse <dwmw2 at infradead.org> writes: > On Fri, 30 Jul 2010, Vivek Goyal wrote: > >> So what happens if we tear down the mapping while DMA is on. > > The DMA gets blocked, and you don't have to worry about whether the device was > shut down cleanly or not. The device may be unhappy, but when the new kernel's > driver loads and reinitialises it, all should be forgiven. Assuming IOMMU page faults don't cause pain. I seem to remember that also being a nasty issue. Eric
