On 16.06.2023 09:10, Stephan Gerhold wrote: > On Thu, Jun 15, 2023 at 02:52:54PM -0700, Douglas Anderson wrote: >> Trogdor devices use firmware backed by TF-A instead of Qualcomm's >> normal TZ. On TF-A we end up mapping memory as cachable. Specifically, >> you can see in Trogdor's TF-A code [1] in qti_sip_mem_assign() that we >> call qti_mmap_add_dynamic_region() with MT_RO_DATA. This translates >> down to MT_MEMORY instead of MT_NON_CACHEABLE or MT_DEVICE. >> >> **Apparently Qualcomm's normal TZ implementation maps the memory as >> non-cachable.** > > Are you sure about this? From the discussion in the chat the conclusion > was that we can check easily for TF-A, but we have absolutely no idea > what Qualcomm's firmware implementation does. It might be "broken" the > same way and we just have not noticed it yet. Nikita (+CC) was able to boot Venus (which uses that memory reservation call, I believe) on next-20230615 with a WP firmware, so it should be okay.. Konrad > > I would perhaps just omit this sentence so we don't risk misleading > someone with information we're not sure about. :) > >> >> Let's add the "dma-coherent" attribute to the SCM for trogdor. >> > > What about sc7280? I guess they use largely the same TF-A firmware? > > Thanks, > Stephan
