On Wed, Mar 27, 2013 at 02:02:44PM +0900, Takao Indoh wrote: > The root cause of this problem is mismatch between iommu->gcmd and > global command register in the case of kdump. At boot time, initial > value of iommu->gcmd is zero as I wrote above, but actual global command > register is *not* zero because some bits like IRE/TE/QIE are already set > in *first* kernel. Therefore this patch synchronize them to fix this > problem. Ok, I understand, but I still don't see why this is a problem. There is no point for the kdump kernel to preserve hardware state from the previous kernel. So I think the way it is implemented is correct. Joerg
