--- zzzz-none-000/linux-3.10.107/drivers/media/v4l2-core/videobuf-dma-contig.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/media/v4l2-core/videobuf-dma-contig.c 2021-02-04 17:41:59.000000000 +0000 @@ -303,14 +303,18 @@ goto error; /* Try to remap memory */ - size = vma->vm_end - vma->vm_start; - size = (size < mem->size) ? size : mem->size; - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - retval = remap_pfn_range(vma, vma->vm_start, - mem->dma_handle >> PAGE_SHIFT, - size, vma->vm_page_prot); + + /* the "vm_pgoff" is just used in v4l2 to find the + * corresponding buffer data structure which is allocated + * earlier and it does not mean the offset from the physical + * buffer start address as usual. So set it to 0 to pass + * the sanity check in vm_iomap_memory(). + */ + vma->vm_pgoff = 0; + + retval = vm_iomap_memory(vma, mem->dma_handle, size); if (retval) { dev_err(q->dev, "mmap: remap failed with error %d. ", retval);