Re: [PATCH 1/2] pxafb: frame buffer overlay support for PXA27x.

On Sat, Sep 13, 2008 at 03:05:40AM -0700, Andrew Morton wrote:

quoted

+static int overlay1fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct overlayfb_info *fbi = (struct overlayfb_info *) info;
+	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;

+	if (off < info->fix.smem_len) {
+		vma->vm_pgoff += fbi->video_offset / PAGE_SIZE;
+		return dma_mmap_writecombine(o1_to_basefb(fbi)->dev, vma,
+					     fbi->map_cpu, fbi->map_dma,
+					     fbi->map_size);
+	}
+	return -EINVAL;
+}

No need to set VM_IO or VM_RESERVED, etc?

That's covered by dma_mmap_writecombine -> remap_pfn_range:

        vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;