If no parameter needs to be modified, make preview_config() and
preview_setup_hw() return immediately. This speeds up interrupt handling
in the common case.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NSakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>