On Thu, Oct 11, 2018 at 4:12 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > On Thu, Oct 11, 2018 at 11:24:49AM +0800, Rock Lee wrote: > > Hi > > I tested direct io with a ion allocated buffer, got a -EFAULT > > error. It turned out that ion_mmap() set VM_IO & VM_PFNMAP, but > > check_vma_flags() (do_direct_IO() calls it) doesn't allow that VMA has > > these flags set. Could you give me any hit that could solve this > > issue? > > > > You must be using an old kernel because ion_mmap() was changed in April. Yes, I am using linux-4.4 which is a little old. Even in linux-4.18, ion_mmap() still callls remap_pfn_range() if the heap is carvout/system/cma/chunk. But remap_pfn_range() set VM_IO & IO_PFNMAP as well. -- Cheers, Rock _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel