On Tue, Mar 05, 2013 at 02:52:39PM +0000, Chris Wilson wrote: > From the w/a database: > > 'To prevent false VT-d type 6 error: > > The primary display plane must be 256KiB aligned, and require an extra > 128 PTEs of padding afterward; > > The sprites planes must be 128KiB aligned, and require an extra 64 PTEs > of padding afterward; > > The cursors must be 64KiB aligned, and require an extra 2 PTEs of > padding afterward.' > > As we use the same function to pin the primary and sprite planes, we can > simply use the more strict requirements for scanouts for both. > > Instead of using explicit padding PTEs following the scanout objects, we > should be able to use the scratch page that is always mapped into the > unused PTEs to avoid the VT-d error. > > References: https://bugs.freedesktop.org/show_bug.cgi?id=59626 > References: https://bugs.freedesktop.org/show_bug.cgi?id=59627 > References: https://bugs.freedesktop.org/show_bug.cgi?id=59631 > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> Reviewed-by: Damien Lespiau <damien.lespiau at intel.com> Maybe rename the mentions to "shadow page" to scratch page as it's the name used elsewhere. I also like the even more explicit function name from Daniel. In any case, sounds like a good patch to have. -- Damien
