Hi Jeffy, Sorry for delayed response. On Mon, Mar 26, 2018 at 1:58 AM JeffyChen <jeffy.chen at rock-chips.com> wrote: > Hi Daniel, > Thanks for your reply. > On 03/26/2018 02:31 PM, Daniel Kurtz wrote: > >> >+struct rk_iommudata { > >> >+ struct rk_iommu *iommu; > >> >+}; > > Why do we need this struct? Can't we just assign a pointer to struct > > rk_iommu directly to dev->archdata.iommu? > > > hmmm, i was trying to add more device related data in patch[13]: > struct rk_iommudata { > + struct device_link *link; /* runtime PM link from IOMMU to master */ > struct rk_iommu *iommu; > }; > > Can't you just add link to rk_iommu directly?