Add support for 'check_flip2' so that the present core can know
why it is impossible to flip in that scenario. The core can then
let know the client that the buffer format/modifier is suboptimal.
v2: No longer need to implement 'check_flip'
Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Acked-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
9d147305b4