[ Upstream commit 24ded292a5 ]
When GEM backing storage is allocated those are normal pages,
so there is no point using pgprot_writecombine while mmaping.
This fixes mismatch of buffer pages' memory attributes between
the frontend and backend which may cause screen artifacts.
Fixes: c575b7eeb8 ("drm/xen-front: Add support for Xen PV display frontend")
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Suggested-by: Julien Grall <julien.grall@arm.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129150422.19867-1-andr2000@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
c1e9cfc815