On Thu, Feb 21, 2008 at 5:43 PM, Markus Armbruster [off-list ref] wrote:

 Fix extracted from this linux-fbdev-devel message:

Hi Markus,

Yes, this was discussed back in November on linux-mm and hence my
patch. I didn't push for it to be merged by itself because I don't
think it makes sense to merge it separately from the full metronomefb
patch. As far as I can tell, only hecubafb and metronomefb seem to be
the consumers.

Out of curiosity, are you using defio or planning to use it? I would
love to hear back from people who are using it.

Thanks,
jaya

    Subject: [PATCH 1/1 2.6.24] fbdev: defio and Metronomefb
    From: Jaya Kumar [off-list ref]
    Date: 2008-02-18 13:41:26

 Signed-off-by: Jaya Kumar [off-list ref]
 Signed-off-by: Markus Armbruster [off-list ref]

 ---

  drivers/video/fb_defio.c |   22 ++++++++++++++++++++--
  1 file changed, 20 insertions(+), 2 deletions(-)

 diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
 index 0f8cfb9..24843fd 100644
 --- a/drivers/video/fb_defio.c
 +++ b/drivers/video/fb_defio.c
 @@ -4,7 +4,7 @@
  *  Copyright (C) 2006 Jaya Kumar
  *
  * This file is subject to the terms and conditions of the GNU General Public
 - * License.  See the file COPYING in the main directory of this archive
 + * License. See the file COPYING in the main directory of this archive
  * for more details.
  */

 @@ -31,7 +31,7 @@ static int fb_deferred_io_fault(struct vm_area_struct *vma,
        unsigned long offset;
        struct page *page;
        struct fb_info *info = vma->vm_private_data;
 -       /* info->screen_base is in System RAM */
 +       /* info->screen_base is virtual memory */
        void *screen_base = (void __force *) info->screen_base;

        offset = vmf->pgoff << PAGE_SHIFT;
 @@ -43,6 +43,15 @@ static int fb_deferred_io_fault(struct vm_area_struct *vma,
                return VM_FAULT_SIGBUS;

        get_page(page);
 +
 +       if (vma->vm_file)
 +               page->mapping = vma->vm_file->f_mapping;
 +       else
 +               printk(KERN_ERR "no mapping available\n");
 +
 +       BUG_ON(!page->mapping);
 +       page->index = vmf->pgoff;
 +
        vmf->page = page;
        return 0;
  }
 @@ -138,11 +147,20 @@ EXPORT_SYMBOL_GPL(fb_deferred_io_init);

  void fb_deferred_io_cleanup(struct fb_info *info)
  {
 +       void *screen_base = (void __force *) info->screen_base;
        struct fb_deferred_io *fbdefio = info->fbdefio;
 +       struct page *page;
 +       int i;

        BUG_ON(!fbdefio);
        cancel_delayed_work(&info->deferred_work);
        flush_scheduled_work();
 +
 +       /* clear out the mapping that we setup */
 +       for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {
 +               page = vmalloc_to_page(screen_base + i);
 +               page->mapping = NULL;
 +       }
  }
  EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);