On Thu, Jan 09, 2020 at 02:27:25PM +0530, Abdul Haleem wrote: > + CC Christoph Hellwig The only thing this commit changed for the dma coherent case (which ppc64 uses) is that we now look up the page to free by the DMA address instead of the virtual address passed in. Which suggests this call stack passes in a broken dma address. I suspect we somehow managed to disable the ppc iommu bypass mode after allocating memory, which would cause symptoms like this, and thus the commit is just exposing a pre-existing problem.