[PATCH 5.3 063/148] drm/atomic: Reject FLIP_ASYNC unconditionally

[Greg Kroah-Hartman]

From: Daniel Vetter <daniel.vetter@xxxxxxxx>

commit f2cbda2dba11de868759cae9c0d2bab5b8411406 upstream.

It's never been wired up. Only userspace that tried to use it (and
didn't actually check whether anything works, but hey it builds) is
the -modesetting atomic implementation. And we just shut that up.

If there's anyone else then we need to silently accept this flag no
matter what, and find a new one. Because once a flag is tainted, it's
lost.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Michel DÃnzer <michel@xxxxxxxxxxx>
Cc: Alex Deucher <alexdeucher@xxxxxxxxx>
Cc: Adam Jackson <ajax@xxxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190903190642.32588-2-daniel.vetter@xxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/drm_atomic_uapi.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1301,8 +1301,7 @@ int drm_mode_atomic_ioctl(struct drm_dev
 	if (arg->reserved)
 		return -EINVAL;
 
-	if ((arg->flags & DRM_MODE_PAGE_FLIP_ASYNC) &&
-			!dev->mode_config.async_page_flip)
+	if (arg->flags & DRM_MODE_PAGE_FLIP_ASYNC)
 		return -EINVAL;
 
 	/* can't test and expect an event at the same time. */