[Mesa-stable] [10.1] Please cherry-pick fixes for fdo#73191

[Andreas Boll]

Hi Ian,

please cherry-pick the following two commits to fix fdo#73191 [1]

Thanks,
Andreas.

[1] https://bugs.freedesktop.org/show_bug.cgi?id=73191


commit 3f98053fc94a964930c73c43154daddfd7824e7c
Author: Marek Olšák <marek.olsak at amd.com>
Date:   Mon Jan 13 14:13:01 2014 +0100

    vdpau: flush the context before exporting the surface v2

    Bugzilla (bug needs XBMC changes as well):
    https://bugs.freedesktop.org/show_bug.cgi?id=73191

    When VL uploads vertex buffers, it uses PIPE_TRANSFER_DONTBLOCK,
which always
    flushes the context in the winsys if the buffer being mapped is busy. Since
    I added handling of DISCARD_RANGE, DONTBLOCK has had no effect when combined
    with DISCARD_RANGE and I think the context isn't flushed anywhere else,
    so no commands are submitted to the GPU until the IB is full, which takes
    a lot of frames.

    Using DISCARD_RANGE is not the only way to trigger this bug. The other way
    is to reallocate the vertex buffer before every upload.

    BTW, I'm not sure if this is the right place for flushing, but it does fix
    the bug.

    v2 (chk): move the flush to the right place.

    Signed-off-by: Christian König <christian.koenig at amd.com>
    Tested-by: StrangeNoises (rachel at strangenoises.org)

commit db54fca9b86aa124447d11d2bdbe359a2742cfd5
Author: Christian König <christian.koenig at amd.com>
Date:   Tue Jan 28 15:22:05 2014 +0100

    st/vdpau: add flush on unmap

    Flush the context when we unmap a buffer, otherwise VDPAU might
    start rendering the next frame while we still reference that buffer.

    Signed-off-by: Christian König <christian.koenig at amd.com>
    Tested-by: StrangeNoises (rachel at strangenoises.org)