Now that we're using lists instead of kfifo to store drm flip-work tasks
we do not need the size parameter passed to drm_flip_work_init function
anymore.
Moreover this function cannot fail anymore, we can thus remove the return
code.

Modify drm_flip_work_init users to take account of these changes.

[airlied: fixed two unused variable warnings]
Signed-off-by: NBoris BREZILLON <boris.brezillon@free-electrons.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Make use of lists instead of kfifo in order to dynamically allocate
task entry when someone require some delayed work, and thus preventing
drm_flip_work_queue from directly calling func instead of queuing this
call.
This allow drm_flip_work_queue to be safely called even within irq
handlers.

Add new helper functions to allocate a flip work task and queue it when
needed. This prevents allocating data within irq context (which might
impact the time spent in the irq handler).
Signed-off-by: NBoris BREZILLON <boris.brezillon@free-electrons.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Describe the fifo parameter. It seems like kerneldoc doesn't properly
handle fields defined using a macro, so it will end up complaining about
this anyway and not generate the documentation for it either. At least
the kerneldoc is now complete.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A small helper to queue up work to do, from workqueue context, after a
flip.  Typically useful to defer unreffing buffers that may be read by
the display controller until vblank.

v1: original
v2: wire up docbook + couple docbook fixes
Signed-off-by: NRob Clark <robdclark@gmail.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>