On Wed, Jul 20, 2016 at 08:49:21PM +0800, honghui.zh...@mediatek.com wrote: > From: Honghui Zhang <honghui.zh...@mediatek.com> > > For mtk iommu, the domain_finalize was called in device attatch, the mtk > iommu iopgt ops was allocated and initialized in domain_finalize, the > iommu_group_create_direct_mappings would call the map interface to > implement the map. If it's earlier than device attach, there would be NULL > dereference. Move the iommu_group_create_direct_mappings call after device > attached.
No, this would open a race window where the device is attached, but doesn't have its unity-mappings in place. You should re-organize the mtk driver instead, so that it works in this order too. Joerg