On Wed, Aug 02, 2017 at 07:05:11PM +0200, Christian König wrote: > Am 02.08.2017 um 18:43 schrieb Jerome Glisse: > > On Wed, Aug 02, 2017 at 10:26:40AM +0200, Christian König wrote: > > > [SNIP] > > So to summarize you are saying you do not trust the value you get from > > pci_map_page() ? > > Well, what we don't trust is that we actually get this value correctly into > our page tables. > > > If not then i stress again that you have all the informations you need > > inside the amdgpu driver. You can take the same scheme i propose to > > dump ttm.dma_address[] and compare against content of GPU page table. > > Yes, exactly. But then again we have the mapping page to dma-address > (because that is what drivers usually need), but what we need for debugging > is a map with the info dma-address to page.
Why would you need the reverse ? You have a GPU virtual address do the following: GPU vaddr -> GPU page table entrie -> bus address GPU vaddr -> bo_va_mapping -> bo_va -> bo -> page -> dma/bus address Compage the 2 values if they are the same then the GPU is looking where you wanted it to look. If they are different then you know you have a bug knowing the physical page addres do not give you any more informations here ? Jérôme _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
