commit 0a646f331d upstream.
Even if the vblank period would allow it, it still seems to
be problematic on some cards.
v2: fix logic inversion (Nils)
bug: https://bugs.freedesktop.org/show_bug.cgi?id=96868
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1f6791d4f2