Hi Daniel, Thanks for your reply. On 04/04/2018 12:11 AM, Daniel Kurtz wrote: > 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? adding link to rk_iommu would be fine if we only have one master device per rk_iommu. but now we are supporting multiple master devices sharing a iommu device :) > > >