On Wed, 2022-06-29 at 12:47 -0700, Nicolin Chen wrote: > On Fri, Jun 24, 2022 at 03:19:43PM -0300, Jason Gunthorpe wrote: > > On Fri, Jun 24, 2022 at 06:35:49PM +0800, Yong Wu wrote: > > > > > > > It's not used in VFIO context. "return 0" just satisfy the > > > > > iommu > > > > > framework to go ahead. and yes, here we only allow the shared > > > > > "mapping-domain" (All the devices share a domain created > > > > > internally). > > > > What part of the iommu framework is trying to attach a domain and > > wants to see success when the domain was not actually attached ? > > > > > > What prevent this driver from being used in VFIO context? > > > > > > Nothing prevent this. Just I didn't test. > > > > This is why it is wrong to return success here. > > Hi Yong, would you or someone you know be able to confirm whether > this "return 0" is still a must or not? > > Considering that it's an old 32-bit platform for MTK, if it would > take time to do so, I'd like to drop the change in MTK driver and > note in commit log for you or other MTK folks to change in future. Yes. Please help drop the change in this file. Sorry I don't have the board at hand right now and I could not list the backtrace where this is needed(should be bus_iommu_probe from the previous debug...) > > Thanks > Nic
