Re: [Linux-fbdev-devel] [PATCH] video: arch specific page protection support for deferred io

[Jaya K. <jay...@gm...>]

On Fri, Jun 26, 2009 at 2:12 AM, Andrew Morton<ak...@li...> wrote:
> On Fri, 26 Jun 2009 02:38:06 +0900
> Paul Mundt <le...@li...> wrote:
>
>> On Thu, Jun 25, 2009 at 12:03:59AM -0700, Andrew Morton wrote:
>> > On Thu, 25 Jun 2009 15:06:24 +0900 Magnus Damm <mag...@gm...> wrote:
>> > > There are 3 levels of dependencies:
>> > > 1: pgprot_noncached() patches from Arnd
>> > > 2: mm: uncached vma support with writenotify
>> > > 3: video: arch specfic page protection support for deferred io
>> > >
>> > > 2 depends on 1 to compile, but 3 (this one) is disconnected from 2 and
>> > > 1. So this patch can be merged independently.
> <hunts around and finds #2>
>
> I don't really understand that one.  Have we heard fro Jaya recently?
>

He's been having some personal problems so he's been quiet. :-)

Magnus's defio changes, #3 look fine to me. I don't know much about #2
but what I understood was that the previous mmap_region code was
unintentionally turning caching back on when it did the writenotify
test and I guess Magnus's goal with the patch is to make sure that
address range is left uncached since sh_mobile uses DMA to transfer
the framebuffer and he might have encountered coherency issues there?

Thanks,
jaya