On 18/10/2021 17:28, Neil Armstrong wrote:
Call drm_atomic_helper_check_plane_state() from the plane
atomic_check() callback in order to add plane state sanity
checking.
It will permit filtering out totally bad scaling factors, even
if the real check are done later in the atomic commit.
I think there's more to it: the function sets plane_state->visible, which is used in later patches.