On 2026-07-01 at 10:17 +1000, Jason Gunthorpe <[email protected]> wrote... > On Wed, Jul 01, 2026 at 07:00:01AM +1000, Dave Airlie wrote: > > > From the production driver, there definitely was some issues in the > > past, however this seems possibly fixed with mmu notifiers, but for > > these memory allocations I'm doing I'm not using MMU notifiers at all. > > Well, the comment on that is this: > > // Fix for Bug 4130089: [GH180][r535] WAR for kernel not issuing SMMU > // TLB invalidates on read-only to read-write upgrades > > And the upstream kernel has that issue fixed, so it looks like that > whole disaster compiles out.
Yeah that whole disaster is something we should never have tried to work around in the driver. However I don't think anything ATS in UVM is related to the problem your trying to debug. UVM ATS deals specifically with SAM/SVM - ie. the ability for the GPU to directly access system allocated memory (think userspace mmap/malloc). This has nothing to do with dma_map/unmap() as these aren't needed for PASID ATS. We're also not using mmu notifiers to workaround any issues like what you have described. - Alistair > Jason
