* Marek Szyprowski wrote: > Hi Thierry, > > On Thursday, April 12, 2012 9:18 AM Thierry Reding wrote: > > Also this doesn't yet solve the vmap() problem that is needed for the kernel > > virtual mapping. I did try using dma_alloc_writecombine(), but that only > > works for chunks of 2 MB or smaller, unless I use init_consistent_dma_size() > > during board setup, which isn't provided for in a DT setup. I couldn't find > > a better alternative, but I admit I'm not very familiar with all the VM APIs. > > Do you have any suggestions on how to solve this? Otherwise I'll try and dig > > in some more. > > Yes, I'm aware of this issue I'm currently working on solving it. I hope to use > standard vmalloc range for all coherent/writecombine allocations and get rid of > the custom 'consistent_dma' region at all. Does your work aim at removing the 2 MB limitation or at remapping non- contiguous memory to a virtually linear buffer? I have some trouble understanding how removing the 2 MB limit would help, because if all buffers can be allocated contiguously then there wouldn't be any need for the IOMMU, right? Thierry
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